Horse Sand Fort is 240 ft across, built between 1865 and 1880, with two floors and a basement the fort is armour-plated all round. During the WW2 an extensive submarine barrier was built in the form of large concrete blocks running about 6 ft below sea level from the fort to the shore at Southsea with only a single narrow gap to allow small craft to pass through, this barrier and a much shorter one running south from No Man’s Land Fort towards Ryde Sands remains as the cost of demolition is too high. Although owned by the same owners as the other Solent forts this fort remains un-restored at this time.