I loved the Fisherman's Bastion and the Matthias Church. We stayed in an apartment near St Stephen's Basilica on my first visit with my family. We did a daylight cruise up and down the river but no food. The second time I stayed in a hostel across the road from Széchenyi Baths and came away from
Budapest wrinkled like a prune. ;-) I didn't even know there were caves under Buda.