Upvote:3
This started out as a comment to the image the OP referred to in another answer.
Looking on Google the end of your proposed taxi ride is apparently called Strandbad Langener Waldsee
. If you google this name you will find lots of good reviews on places like Trip Advisor saying that it is a nice, clean place to spend some time swimming. Summarizing what I saw from various reviews:
I was not able to determine if you are able to rent towels or beach umbrellas.
What I would caution is spending 1/2 day in the sun at the beach before a long flight. Sunburnt children on a plane
sounds like the plot of a horror story!
On the other hand, sleeping under a tree/umbrella before your flight sounds like a great way to relax.
Upvote:5
Frankfurt airport is well connected to the city of Frankfurt by trains, which take only 11 minutes and run every 15 min or so. So you can easily go explore the city and come back in time for your flight, particularly if one or more of your flights is a "Euro-domestic" Schengen flight with no immigration to pass through (since this is the one place in Frankfurt that occasionally gets jammed).