The Old City of Valencia was contained behind defensive walls until 1865. They were then demolished and replaced with broad, modern boulevards and widened, remodelled squares. But these two sturdy, crenellated towers, guarding a narrow gateway, are the most substantial and eye catching survivors of the medieval walls. They were built between 1392 and 1398 and for three centuries they were used as a prison for knights and nobility. Climb them and you can see across the Old City and the former Riu Túria. The view is almost as spectacular as that from the top of the Micalet, but it won't leave you gasping for breath.