" To lay a foundation" means to put usually concrete or some sort of stone on the ground, and usually underneath the ground, to support the house, to support the weight of the house.
And I realized that I really like to follow things I'm passionate about versus sort of the rigor of studying like the fundamentals all across the board and building up and castle.
They discovered Herculaneum while digging to lay a foundation for a royal palace, and they quickly began looking for other cities that had been buried.