* Thomas Monticello is a house designed by Thomas Jefferson, the third President of the United States, and built in Virginia. It is known for its neoclassical architecture and its connection to Jefferson's ideals.
* The Pantheon is a temple in Rome, built in the 1st and 2nd centuries AD. It is famous for its dome, which was the largest unreinforced concrete dome in the world for centuries.
While both structures have neoclassical elements, they have different purposes, histories, and architectural features. The Pantheon is a temple dedicated to all the gods, while Monticello is a private residence. The Pantheon's dome is a key architectural feature, while Monticello's dome is more modest and serves a different purpose.
Perhaps you are thinking of another structure or concept. Could you please clarify your question?