Building inspectors were dispatched to determine if it was safe for the guests to remain in the building.
The 4.7 magnitude tremor struck just seconds after noon local time about 95 miles (155 km) north-northwest of Athens at a depth of 26 miles (42 km), according to the U.S. Geological Survey.
The Athens Geodynamic Institute placed the epicenter directly beneath the Corinthian Gulf, off the city of Aigion.
Shaking was felt across the north of the Peloponnese, but no injuries were reported.