I grew up on that lake, maybe I can offer some advice. For bikini's definitely go to the Park south beach.
If you are thinking about fishing then I know more about the Upper Maz vs the lower.
Lake trout - best fished in early spring, hard to catch in summer. Head of the Upper lake is good - run from the Marina towards Brown's camp. Good luck.
For walleye, only early morning or evening will work. Worm harnesses, yellow or white. Walleye are there in numbers like they were years ago. MNR insists that this is a trout lake and are happy to see a decrease in the walleye.
Recommend along south side Bear island to partly across German Bay.
Campbell's bay north shore; run 15 - 20 fow. Watch your depth - about 1/2 way down the north shore the is a shoal that will push you way off shore.
Bottom of Campells from the creek around to the south shore and around the island with the white cottage. Wave politely to Mr. Moe.
Don't bother trying to catch walleye around the narrows. too many boats and the fish there are only there to sight-see.
If you are working the south shore of Campbell's bay be very careful or use charts. Most of this lake is very deep be careful.
Beautiful area, take a walk up the mountain stairs.