Mat Bienczyk

You can get some very neat views of the Frankfurt skyline from the south side of the river. Simply walk along the promenade and shore and you'll get some great views, with or without the bridges.

Fantastic metal bridge to get across Main River, between the two shores. There's plenty of locks on the bridge. It's very close to the main promenade and old town.

A large wire bridge for walking and biking across river main. Also a great spot to get some panoramic views of Frankfurt and the surrounding buildings and architecture.

Definitely worth visiting the Main Tower if in Frankfurt - you can either do this during the day, or right before sunset to get some phenomenal skyline views of the city. Depending on the hour (of weekend), there could be a pretty long wait of up to 20min or so. Getting tickets beforehand didn't really change as you'd still end up in line to get to the counter.

Island Lake Conservation area is a pretty large park with plenty of walking, hiking, and picnic areas; a large lake for fishing, canoeing, or kayaking. There is an entrance fee per person to the park, but well worth it to maintain the park and area. The longest walk around the lake across several boardwalks takes about 1.5-2h. Highly recommend also spending some time at the nature park.