The Eyüp Sultan Mosque is a significant Islamic shrine in Istanbul, honoring Abu Ayyub al-Ansari, a companion of Prophet Muhammad. It's a deeply spiritual place, especially during Ramadan. The mosque complex includes tombs, a cultural center, and traditional shops. It is generally accessible, though crowded, particularly on weekends. A solo visit is perfectly fine, allowing for personal reflection, but guided tours can offer deeper historical and religious context. There are no specific seasonal restrictions, but dress modestly (covered shoulders and knees) and remove shoes before entering. Entry is free, but donations are welcome. A typical visit lasts 1-2 hours.