There is parking available for about twelve motorhomes at the top of Grimsel Pass. It offers a nice view of the lake and dam, located away from road noise. The cost is 10 CHF per day, and you can pay at the nearby hotel, which has toilets and showers.
A unique parking spot is available at the Alpenlodge. Payment is 25 CHF by card. The owner is friendly and provides thorough explanations. If possible, drive the Oberaar panoramic road to Berghaus Oberaar by Oberaar Lake for a great experience.
The cost is too high at 20 Swiss Francs. Restrooms are only available when the restaurant is open, and there are no showers or washing facilities. Electricity is limited to a few campers.