With the Swiss board 1.5 km up the road you can explore 2 countries very easily from Chatel.
The famous city of Geneva is a very scenic 80 minute drive away.
Please follow this link to the Geneva tourist information site which gives lots of information on all the things you can experience there:-
Lake Geneva (Lac Leman) and Surrounding Area
There are numerous towns and villages to visit on the shores of Lake Geneva including Montreux and Evian. The lake itself is one of the largest in Europe and is up to 13km wide in places.
Whilst we haven't visited Yvoire ourselves yet, many people have recommended we do. It's a medieval village on the banks of Lake Geneva about 54 km from Chatel, and looks gorgeous.
Thonon-les-Bains is ideal to visit being a very pretty 45 minute (38km) drive mostly following the River Dranse. You can picnic by the lake, visit the thermal baths or hire a small boat. The tourist office gives more information at this link:-
Salt Caves At Bex
For an interesting trip out can visit the salt caves at Bex, about 25 km. Being underground this is an ideal trip to do if it's raining.
It's worth checking the times of the tours as they a run in several different languages at different times. Here's a link giving full details:-
There are numerous different lakes to visit in the area, some suitable for sunbathing and swimming.
Aquaparc Le Bouveret
Whatever the weather this exciting water park is heated to 28° C and is open all year. It's by Lake Geneva about 37km from Chatel. See their site for fully details:-
One of our favourite is Lake Annecy which is worth the 112 km drive. The historic town of Annecy is a delight to explore.