Information regarding park at Lake Obernberg at the end of the page.
The Obernberger See is a mountain lake at 1590 m, 40 minutes by car and another 30 minutes by foot from Innsbruck. Despite the proximity to Innsbruck, the lake is relatively lonely and there are usually only a few visitors. The water is usually too cold for swimming.
A walk around the lake takes about 60 minutes, depending on the water level (in addition to the 30 minutes from the parking lot to the lake). However, the impressive landscape always invites you to rest, and so you should take half a day off for this excursion.
It is also worth seeing Chapel Unserer Lieben Frau am See, which was built in 1935 on a peninsula in Lake Obernberg.
Info
How to get there: 40 minutes by car from Innsbruck to a large paid car park just after Gereit. There is usually enough parking space, even on weekends. Then 30 minutes walk along a country road or steep path (shortcut).
Services: There is a toilet and a little Restaurant at the parking lot (it is not always open). At the lake itself there is no toilet, shop or anything else.
External Link: Municipality of Obernberg am Brenner – State of Tyrol