Byodo-in Temple is one of two World Heritage locations in Uji and rightly famous for its spectacular Phoenix Hall or Hoo-do. I found the temple grounds super impressive, especially in spring! Depending when you visit you will be greeted by a weeping cherry blossom or wisteria. I loved strolling these grounds and soaking in the tranquil atmosphere. While not being a hidden gem we found this place not crowded at all (we visited around noon!)
To enter the temple buy a 600 yen ticket which grants you access to the temple grounds and museum.