There is a lot to see in the Borghese Gallery but the main reason to reserve tickets to visit is to see the unbelievable Bernini sculptures, particularly, Apollo and Daphne, and Poseidon and Persephone. The exquisite skill demonstrated in those works is amazing. The thin leaves growing from Daphne's fingers and the pliant flesh on Persphone's thigh makes it almost impossible to believe these are marble sculptures. And of course, they will never be moved from the site, so the only way to see them is to visit.