checkpoint; barrier station
Historical term for a checkpoint on major roads during the Edo period and earlier, where travelers were inspected and tolls collected. Often used in historical contexts or figuratively for a strict inspection point.
江戸時代には、街道に関所が設けられていた。
During the Edo period, checkpoints were set up on the highways.
旅人は関所で通行手形を提示しなければならなかった。
Travelers had to present their travel permits at the checkpoint.
関所 refers specifically to a historical checkpoint or barrier station, while 関門 can describe a modern, geographic, or purely figurative gateway.
breaking through a checkpoint; sneaking past a barrier
Compound of 関 (seki, 'barrier') and 所 (sho, 'place'). The reading せきしょ is a standard on'yomi combination.