The small archaeological museum is conveniently placed on the way back to Platanos Three employees sit on the doorstep outside but get up in a hurry and go to their posts as we arrive Admission is free so they are not here to sell tickets

Could you correct the punctuation please?
The small archaeological museum is conveniently placed on the way back to Platanos. Three employees sit on the doorstep outside, but get up in a hurry and go to their posts as we arrive. Admission is free, so they are not here to sell tickets.