tl;dr: A Tilehurst property is up for auction at £300K-£325K featuring a 1,300+ sq ft network of hand-dug tunnels extending 15m underground across four levels, built by civil engineer Tony Deane and his six children over two decades using only buckets and wheelbarrows. The complex includes a hand-built railway, a one-tonne goods lift, secret doors (including a 1.5-tonne sliding concrete wall), and an entrance hidden inside a 23ft rocket by the pool. The auctioneer suggests potential uses ranging from secure storage to an EMP-resistant data center.