Its 15 per person, you can visit his factory-museum, and also you can go to his mansion,which is 2 minutes y car. Mansion includes in this money, it's on the private territory, so employees should give pass card for car
It was open for the public until the government shutdown. Yes, there are entry fees.
Did you call them? We can provide information based on our experiences. For information you can get from the website or calling, you should try that. Under 16 is free but you would also get that from the website.
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