These are so common in England they have a name: follies.
Typically named after (often Victorian) idle playboy who built them, and often with no attempt made to conceal their origins; they are only as "medieval" as the tastes of the playboy ran (so, more Tennyson than Terry Jones).
Typically named after (often Victorian) idle playboy who built them, and often with no attempt made to conceal their origins; they are only as "medieval" as the tastes of the playboy ran (so, more Tennyson than Terry Jones).