A derelict 19th-century fortress on Wales’ Thorne Island has been transformed into a luxury event venue after a five-year renovation, now listed for £3 million. Former tech CEO Mike Conner overcame significant challenges to convert the Napoleonic-era fort into a party space featuring 40 beds, four en-suite bathrooms, and a nightclub.
Purchased for £555,000 in 2017, the fortress had been abandoned for 17 years with no running water or electricity. Conner invested heavily in infrastructure, including £200,000 just to install a functional sewage system by cutting through 16 feet of rock. The location near Milford Haven in Pembrokeshire required materials to be helicoptered in, with workers living on-site for weeks at a time.
Originally built in the 1850s to defend against French naval attacks, the fortress later operated as a hotel from 1947-1999 before falling into disrepair. The renovation preserved historic elements while adding modern amenities, creating a unique venue that has hosted events ranging from intimate gatherings to an 80-person festival featuring a tightrope walker.
Conner emphasized the property’s transformation into an ‘off-grid’ experience where guests disconnect from technology. The island offers complete privacy with no neighbors, allowing unrestricted events. During renovations, Conner discovered his own Welsh heritage through family connections to nearby Upton Castle.
The property is now marketed as a blank canvas for its next owner, with potential as a tourist attraction, exclusive event space, or even large-scale rave venue accommodating up to 800 people. Conner believes the venue could generate significant revenue while showcasing Welsh heritage.
The sale represents both a personal milestone and a preservation achievement, rescuing a Grade II-listed building. Conner stated he’d ‘crawl over broken glass’ to attend future events, reflecting his emotional connection to the project that provided an ‘incredible’ escape from corporate life during COVID-19.