Mercado da Riberia is Lisbon's idea of an indoor farmers market, and while pretty respectable, it's rather ordinary in size-- again, we sort of forgot just how small of a city Lisbon is! The walk there was fairly quick though, passed through a mini-red-light district attached to a tiny restaurant row (food was quite decent) that we hit both for lunch and later for dinner.
Visited the Oceanario in the afternoon. Lisbon's bus and tram system is quite good, and the aquarium's centerpiece, a huge ocean tank viewable from all four sides plus upper and lower levels, with a sunfish (!) and a manta ray as two of the highlights, is amazing. Well worth the visit as it was easily as impressive as Monterey Bay Aquarium, yet in a very unique way.
Wandered historic Lisbon some more in the late evening, enjoying the Christmas lights and the relatively light crowds off the off-season.