I think historical sites should be open to the general public.
For one thing, this gives people the chance to learn historical and cultural knowledge. By visiting those sites, people can know what food people ate in the past, what tools they used when foraging, what was people’s life like in different empires, which is beneficial to both adults and children.
For another thing, this brings economic benefits. By opening to the general public, visitors will beat tracted and will pay ticket money for those sites, then those sites will have more money to do the maintenance and repairs, better protecting those historical relics.