guérite

Demandez à la guérite là-bas.

Ask at the police box over there.

Le gardien ferma soigneusement la porte de sa guérite – je n’en vis guère l’utilité – et, avant de partir, se mettant dans la peau d’un étranger, il essaya de l’ouvrir

The guard carefully closed the door to his sentry-box - I failed to see the point of it - and, before leaving, pretending to be a stranger, he tried to open it.