At the recommendation of one of our hotel wait staff, we visited the Amador Causeway on Sunday where the local ritual consisted of biking, walking/strolling, and the general being outdoors to enjoy the beautiful scenery. The Causeway offers great views of the metropolis across Panama Bay and seeing it on a bike was truly enjoyable. We initially wanted to rent a bike at the north end of the Causeway but our Uber driver recommended we go to the one that was near the Taboga Ferry area, so we rented one from Burke Bikes instead (make sure you bring an ID of sorts, driver's license worked for us since we didn't know we needed a passport so that was lucky!). Bike rentals there were normal, I guess - we did a 3-passenger tandem side-by-side bike for $10/hour plus $2 for tax (or something else). If you did the usual mountain bike, it was $4/hour. Biking from that spot to Isla Flamenco took all of 20 minutes and then we rode back up towards BioMuseo for the rest of it before having to bring the bike back to the shop. You can do all of this in an hour if you rode like a maniac, which we did (we also raced a cargo ship that was leaving the canal :)) After we returned the bike, we walked back to Isla Flamenco since we were told that on Sundays you can catch a few exotic cars and eat at Alberto's with the Panama Yacht as your view. We saw a couple of Ferraris, Lamborghinis, and a McLaren, so the husband was pleased.
Overall, a very nice way to spend your Sunday here - we got lucky with the weather and a good way to enjoy the outdoors for several hours.