Timanfaya National Park has some cool looking hikes, but they're reserved weeks in advance-- oops. Ended up on the much more accessible bus tour, which do a figure-eight around a bunch of the more well known cinder cones/craters in the park. Not quite the up close and personal experience I would have preferred, but had to take what I could get. The restaurant/gift shop does do a good job showing off how much cooking they do with the volcanic heat, probably to maximize the appeal to the all the tourists.
La Geria's wineries were the next stop, just a short drive from Timanfaya National Park. Ended up a bit too early in the day for the proper experience, but was nice to properly soak in the views before running off to the airport. Saw some potential for much better food than the tourist traps there as well, then I found out the kitchens didn't open til 1:00pm. *sigh*
The quick hop from Lanazrote to Gran Canaria was next-- felt like going from Kauai to Oahu. Instead of a surface parking lot, it's a massive parking structure serving the airport, and when you exit, you end up on what feels like a massive freeway and not just an expressway. It's a decent 30 minute drive with traffic to the sand dunes at the south end of the island (Dunas de Maspalomas) as you wind down the coast. The tourist town behind the dunes isn't too big, but then, neither are the sand dunes or the beach. You can get some views where the dunes seem to stretch on for miles, but in reality people are mostly juuuust out of frame, and the beach is refreshingly natural and the water is warm.
Aimlessly wandered the dunes for a few hours before dinner, not sure if that's how tourists do it but it seemed reasonable? Not quite as nice was another disappointing meal, headlined by a proper Spanish tortilla that decidedly did not hit the spot, the fish dinner was similarly blah. As sunset came, headed back up the coast to Las Palmas and the hotel, which was the only Marriott on the island. The AC Hotel by Marriott in Las Palmas is architectural tower with smallish rooms and a surprisingly affordable price for an AC at less than EUR 100 a night. The view of the harbor (and the freeway, and the mall between the freeway and the harbor...) was actually not bad too, although the location was otherwise not memorable.