moon bridge; semicircular bridge
A bridge whose semicircular arch, together with its reflection in the water, forms a full moon shape. Used in traditional Japanese gardens and architecture.
The moon bridge in Koishikawa Korakuen Garden is a famous sightseeing spot.
Compound of 円月 (engetsu, 'full moon') + 橋 (kyō, 'bridge'), referring to the circular shape formed by the arch and its reflection.