Andorra la Vella is quite interesting to see, the rest is just ski resorts and agglomerations of huge duty-free stores calling themselves towns. If you’re into that, ok… But be advised that, if you don’t book a return trip from Barcelona or Toulouse, they seem to do everything to prevent you from leaving the country. We tried for one whole day, starting at 4:30 am – the buses either didn’t go at the times we’d been told or they didn’t go at the places we’d been told or they didn’t go at all. We had to change our further travel plans and skip other things just because they’re not able (or willing) to provide any decent public transport. So I do think it was kind of interesting, but in the end it wasn’t worth the hazzle for me.