
We'll start from Rocca Pia, a fortress of the 15th century in the city center. It was buil in a year by order of Pope Pio II. Northern to the Rocca Pia there was the Anfiteatro di Bleso, an amphitheater, but it was took down to prevent enemies to find shelter in it. However, you can still visit the remains, not far from the fortress.
While you can visit the amphitheater, Rocca Pia is not open to the public yet, but you can still admire its 4 tower on the outside.

There are also many other fountains and the garden is very wide. You can visit both the Villa and the garden with a 11 euros ticket and you can book your visit at Villa d'Este official site.
Follow now via della missione, turn left in via dei selci and you will arrive at the Duomo of Tivoli (Saint 4 chapels and other two are in the north side.
Lawrence Cathedral), built in Baroque style in 1650. The bell tower though belongs to a prior version of the church, built in Romanesque style in the 1st century BC. The interior, the vault and the apse presents paintings of the 1700s and 1800s. On the south side of the Cathedral there are
Finally, following via san Valerio and then via ponte gregoriano we arrive at Villa Gregoriana, famous for its park. You can have a tour of the park, starting from the bridge and then visiting the Valle dell'inferno (Hell's valley) where grottoes are found as well as 2 ancient temples. You will also enjoy the view of beautiful falls. The tour lasts about 90 minutes and costs 6 euros per person or 15 euros for families: more information in the official site of FAI (Found for the Italian Environment) Be sure to wear good footwear and bring some water with you as the tour will be almost entirely in the park, with uneven paths.
I hope you enjoyed the tour, comment down below any question or suggestion. Bye!