Rabati Castle has been comprehensively renovated from the perilous, semi-ruined state it was left in a decade ago, and while it was a much-needed investment, sadly what greets you today feels a bit Disneyfied. You'll enter through the eastern, lower part of the complex, which doesn't require a ticket but is where you should buy one for the upper castle with its mosque, citadel and museum. A tour is a good idea to bring things alive.
Ponds and colonnaded pavilions are set before the stone-and-brick Ahmadiyya Mosque and two-storey medrese (Islamic school), built in the 1750s. The mosque (no longer used for religious purposes) now sports a dazzling new gold dome. Up to the left rise the citadel and the Samtskhe-Javakheti History Museum, which spans the aeons from the 4th-millennium-BC Kura-Araxes Culture to 19th-century regional costumes.
