With the expansion in the volume and variety of spatial data and the increasing reliance of geospatial information systems (GIS) on web-based platforms, the need for secure, transparent, and trustworthy structures for data storage and exchange has become more pressing than ever. Conventional centralized architectures, despite their ease of implementation and management, face challenges such as centralization, security vulnerabilities, and reduced accessibility. This study investigates the utilization of blockchain technology as a decentralized and tamper-resistant platform to address these challenges. First, the study reviews the related literature on the integration of blockchain with GIS and analyzes the shortcomings of existing blockchains in meeting the specific requirements of this domain. Then, an initial design of a blockchain-based GIS is presented, with its architecture specifically tailored to the sharing of spatial data within this framework. In this system, the Well-Known Binary (WKB) format is selected for storing spatial data, and a simplified Proof-of-Work consensus algorithm is employed to coordinate among nodes. The system is implemented at the proof-of-concept level using the Python programming language and the Flask framework. The proposed approach can serveas an effective step toward the development of dedicated blockchains for the exchange and sharing of spatial data and provides a suitable foundation for future research aimed at enhancing the scalability and performance of GIS.