Bagnaia started its existence as a castle, around which a settlement developed. The original part was built on a rocky outcrop with steep cliffs, which meant that one could only enter from one side, which was protected by solid walls. The only entrance is the gate next to the round tower.
Bagnaia was founded before the year 1000, but was never independent. First it was controlled by German princes, then it came under the municipality of Viterbo and later still under the power of bishops.
It was only when the Villa Lante was built in the Renaissance period, that Bagnaia began to expand beyond the city walls.
Bagnaia‘s biggest attraction is the Villa Lante, with a large number of interconnected fountains.
Other attractions are the Madonna del Rosario Church and the Fontana dei Mori.