Announcement PDF 23 June 2026 US$3M+ HISTORICAL DATASET FAST TRACKS NIELLE DRILL TARGETING Full historical dataset comprising RC drilling, air core drilling, geochemical sampling, mapping and technical studies along a 4.5km gold trend HIGHLIGHTS ▪ Castle has received the complete historical exploration dataset for the Nielle Gold Project reflecting an estimated US$3+ million expenditure by previous exploration groups. ▪ Dataset includes 40 RC drill holes (4,420m), ~7,000m of air core drilling, geological mapping, geochemical sampling, technical studies and retained drill samples. ▪ Historical exploration identified multiple zones of gold mineralisation over a strike extent exceeding 4.5km, providing a strong technical foundation for systematic follow up exploration. ▪ Experienced geologist George Michaelides, who has direct firsthand operational knowledge of Nielle from previous explorationactivities, hasbeen appointedExplorationManager to accelerate drill target definition. ▪ Receipt of the historicaldataset significantly reducesthe time required to advance Nielle towards drill testing following grant of the exploration licence. Castle Minerals Limited (ASX: CDT) (“Castle” or “the Company”) is pleased to advise that it has received the complete historicalexploration dataset relating to the recently acquired Nielle Gold Project in Côted'Ivoire (“Nielle”). The dataset comprises exploration information generated between 2015 and 2021 and includes RC drilling, air core drilling, geological mapping, geochemical sampling, technical studies, supporting exploration Steve Zaninovich, Managing Director of Castle, commented: “The acquisition of this extensive historical dataset and physical sample inventory materially de-risks the early stages of exploration at Nielle and provides Castle with a substantial body of technical information from which to rapidly advance drill target generation. Historical exploration has identified high grade gold mineralisation over a strike length exceeding 4.5km, highlighting the scale of the opportunity and reinforcing our belief that Nielle has the potential to become a significant gold project. George Michaelides' appointment further accelerates that process. Having previously worked on the project, George brings direct knowledge of the geology, exploration history and key target areas, allowing Castle to move efficiently from data review to drill planning. Castle’s focus is now on completing a technical assessment of the historical information, generate targets and prepare for a maiden drilling campaign as soon as the licence is granted.” databases and retained drill samples. Castle estimates that the historical work undertaken by previous operators represents more than US$3 million in direct exploration expenditure. The receipt of this comprehensive dataset materially advances Castle’s understanding of the project and provides a substantial head start in progressing exploration planning and drill target definition. To assist immediately with the review and interpretation of the historical Nielle exploration data, Castle has appointed experienced geologist, George Michaelides, in the role of Exploration Manager. Mr Michaelides has intimate knowledge of the Nielle concession having previously been involved in the exploration activities undertaken on the concession by prior operators, and over 25 years’ experience in field exploration with more than half of that in West Africa including Côte d'Ivoire, Mali and Senegal. He will work closely with the Castle team in utilising the historical exploration data to assess exploration targets and formulate a maiden drilling program at Nielle. Nielle History Nielle encompasses ~212km2 of prospective tenure under application in Côte d'Ivoire. Nielle is located in Birimian terrane in the Senoufo greenstone belt, a globally significant geological province that hosts many of West Africa’s major gold deposits, including the proximal operating gold mines at Tongon (5.0Moz), Sissingué (1.5Moz), Wahgnion (3.2Moz) and Syama (11.5Moz) (Figure 1). Figure 1: Nielle Project Location, regional operating gold mines and Castle existing licence areas The nearby Tongon Gold Mine located ~50km to the south of Nielle, has been in continuous operation since 2010 and produced an average of 250,000 Au oz/pa over its first decade at a head grade of 2.20 g/t Au. Previously owned and operated by Barrick, Tongon was acquired by the Atlantic Group in 2025 for US$305 million, underscoring the strategic value of established gold assets within the region. Historical modern exploration activities commenced at Nielle in 2015 following the commencement of exploration programs by previous permit holders and joint venture partners. Exploration activities completed over the project area included geological mapping, geochemical sampling, air core drilling and reverse circulation drilling programs designed to test multiple gold targets across the concession. Castle notes that historical exploration programs identified multiple zones of gold mineralisation associated with alteration, sulphide mineralisation and quartz-carbonate veining within a prospective Birimian greenstone belt setting. The Company considers the historical work completed to date to be highly encouraging and indicative of a potentially significant gold system warranting further systematic exploration. Further details regarding the historical exploration results were disclosed in the Company's ASX announcement dated 19 May 2026, titled "Castle Acquires Highly Prospective Nielle Gold Project in Côte d'Ivoire".Investorsare referred tothat announcement fordetails ofthe historical highgradeexplorationresults and associated cautionary statements. Forward Work Plan Castle will now undertake a detailed technical review of the historical exploration information with the objective of defining and prioritising drill targets. Work programs currently being assessed include: • review and validation of historical drilling and geochemical datasets; • geological and structural interpretation; • drill target generation and ranking; • metallurgical assessment utilising retained drill samples; and • supplementary geochemical programs where required. The combination of extensive historical exploration and demonstrated high grade gold mineralisation, a large prospective landholding and excellent regional geological setting provides a compelling platform from which Castle will pursue resource definition. Castle continues to work closely with Golden Arrow SARL regarding completion of the remaining conditions precedent associated with grant of the Nielle permit, as outlined in the Company's announcement dated 19 May 2026. - END - This announcement was authorised for release to the ASX by the Board of Castle Minerals Limited. For further information please contact: Steve Zaninovich Managing Director enquiries@castleminerals.com About Castle Minerals Castle Minerals Limited (ASX: CDT) is a West African focused gold explorer with tenure positions in Côte d'Ivoire and Western Australia, two of the world's premier gold producing regions. The Company has proposed changing its name to Terranova Metals, subject to shareholder approval. In Côte d'Ivoire, Castle is contracted to earn interests in eight permits (one granted, seven under application), including the flagship Nielle Gold Project in the north. The remaining "CDI East" permits sit along the Côte d'Ivoire–Ghana border. All are located on fertile Birimian greenstone belts that host numerous multimillion- ounce gold deposits across West Africa. Figure 2: Castle Minerals tenement package in Côte d'Ivoire In Western Australia, Castle holds a dominant, contiguous ~184km² landholding in the Murchison Gold District, a proven province hosting multiple operating and past producing mines. Its Meeka South Gold Project carries a clear infrastructure advantage, sitting close to the Bluebird Gold Processing Mill (Westgold) and Meeka Metals' Murchison Gold Project, with geology comparable to established regional producers. Figure 3: Castle Minerals Meeka South tenement package in Western Australia Exploration Results This announcement does not report any Exploration Results. References to historical exploration activities are provided for background information only. Historical Exploration Results associated with the Nielle Project were previously disclosed in the Company's ASX announcement dated 19 May 2026. The Company is continuing its technical review of the historical dataset and has not yet completed the work necessary to independently verify all aspects of the historical exploration information. Cautionary Statement All of Castle’s projects in Côte d'Ivoire, Ghana and Australia are considered grassroots or at a relatively early stage of exploration. There has been insufficient exploration to define a Mineral Resource. No Competent Person has conducted sufficient work in accordance with JORC Code 2012 to determine conclusively or to estimate in what quantities gold or other minerals are present. It is possible that, following further evaluation and/or exploration work, confidence in the information used to identify areas of interest may be reduced when reported under the JORC Code (2012). Forward Looking Statement Statements regarding Castle’s plans, forecasts and projections with respect to its mineral properties and programmes are forward looking statements. There can be no assurance that Castle’s plans for the development of its mineral properties will proceed. There can be no assurance that Castle will be able to confirm the presence of Mineral Resources or Ore Reserves, that any mineralisation will prove to be economic or that a mine will be successfully developed on any of Castle’s mineral properties. The performance of Castle may be influenced by factors outside the control of the Company, its directors, staff or contractors.