]A multichain non-fungible tokens (NFTs) marketplace is a decentralized platform where users can buy, sell, and trade NFTs across multiple blockchain networks by using cross communication bridge. In past most of NFT marketplace was based on singlechain in which NFTs have been bought, sold, and traded on a same blockchain network without the need for any external platform. The singlechain based marketplace have faced number of issues such as performance, scalability, flexibility and limited transaction throughput consequently long confirmation times and high transaction fees during high network usage. Firstly, this paper provides the comprehensive overview about NFT Multichain architecture and explore the challenges and opportunities of designing and implementation phase of multichain NFT marketplace to overcome the issue of single chain-based architecture. NFT multichain marketplace architecture includes different blockchain networks that communicate with each other. Secondly, this paper discusses the concept of mainchain interacting with sidechains which refers to multi blockchain architecture where multiple blockchain networks are connected to each other in a hierarchical structure and identifies key challenges related to interoperability, security, scalability, and user adoption. Finally, we proposed a novel architecture for a multichain NFT marketplace, which leverages the benefits of multiple blockchain networks and marketplaces to overcome these key challenges. Moreover, proposed architecture is evaluated through a case study, demonstrating its ability to support efficient and secure transactions across multiple blockchain networks and highlighting the future trends NFTs and marketplaces and comprehensive discussion about the technology.