The observatory itself will not take much time to look round during the day - an impressive telescope in a very cool dome with a few other bits of info. The museum is not very big, though what there is on display is interesting enough. It would all probably be much better if you could go at night and actually see the telescope in use, so plan ahead!! The road up and down the mountain is fabulous though - worth the drive even if you don't get into the observatory! We went at a weekend, so there were an awful lot of bikers around making the most of the hairpin bends - something to watch out for (though it might have been a planned gathering, as there were photographers on some of the corners)
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