Across the valley is the alpine massive of Eiger, Moench, Jungfrau. There is a train that goes up there to the glacier which terminates in the highest train station in Europe, again with great views. It involves going back down into the valley via the Stechelberg gondola (the same you just took up the mountain - jut the other way), and taking a short bus ride to the "Jungfrau-Bahn" (Jungfrau-railway) station in 'Kleine Scheidegg'.
One thing you wouldn't wanna miss is a original Swiss Fondue in one of the restaurants in Muerren - but it can be taxing your travel budget. Mürren has some of the best restaurants in Switzerland including - curiously enough - *the* best Chinese restaurant.There is also a spa in town, that you can check out. It wasn't very warm when we were there, but that could have changed in the meantime.
I'd say stay at least 2 nights, maybe 3 in Muerren. There is more info at [https://muerren.swiss/en/ this web site]