Chashma-Ayub — "Spring of Job" — is a mausoleum and sacred spring located in the park next to the Samanid Mausoleum, just outside the old city walls. The current structure dates mostly to the reign of Timur in the late 14th century, though parts are older, and its unusual conical dome — different in style from anything else in Bukhara — reflects the influence of Khorezm architects brought in by Timur.
Inside, the building houses a small water museum alongside the shrine. The spring is accessible through an opening in the floor, and the water that flows from it is strikingly cold and sweet-tasting even in summer. Most visitors to Bukhara combine a visit here with the adjacent Samanid Mausoleum; the two monuments are a short walk from the Ark and make a logical morning excursion from the Lab-i-Hauz area.