These İstanbul mosques are often overlooked because they lack the size and splendor of their much more popular counterparts. However, some are fine buildings in their own right and are well worth a visit. Here are a number of such mosques:

The Yeni Valide Mosque is among the many gems of Üsküdar, whose history dates back to 5000 B.C. The mosque was built on the orders of Emetullah Râbi’a Gülnûş Sultan, the mother of Sultan Ahmed III, by architect Mehmet Ağa between 1708 and 1710. This mosque is where Turkish Islamic scholar and intellectual Fethullah Gülen delivered his “Sonsuz Nur” (Eternal Light) sermons.

The Ayazma Mosque, also in Üsküdar, awaits its visitors with its history dating back some 250 years. This mosque was built by Sultan Mustafa III in honor of his mother, Mihrişah Sultan.

Yet another mosque crowning a hilltop in Üsküdar is the Valide-i Atik Mosque, one of the masterpieces of the great Ottoman architect Mimar Sinan. Valide-i Atik was built under the orders of Nurbanu Sultan, the wife of Sultan Selim in the 1570s. The mosque and the social complex around it included a madrasah (religious school), a dervish lodge, an elementary school, a caravanserai (road-side inn), a Turkish bath, a darulkurra (an institute specializing in the recitation of the Quran) and a hospital. Currently, only the mosque and the Turkish bath continue to serve the city’s residents. The location of the mosque ensures that it receives relatively few visitors, yet it is well worth visiting.

Climbing up from Barbaros Boulevard toward Yıldız in Beşiktaş, you will see an elegant minaret rising modestly to the sky on your right. This single minaret belongs to the Yıldız Hamidiye Mosque -- or the Yıldız Mosque, as it is more commonly known to the public. Commissioned by Ottoman Sultan Abdülhamid II, the mosque was constructed between 1884 and 1886 by Nikogos Balyan, the chief imperial architect of the time.

People visiting the famous Sultanahmet (Blue) Mosque can also visit the Küçük Aya Sofya Mosque (Little Hagia Sophia), which is just a short walk downhill from the Blue Mosque. Küçük Aya Sofya started life as the Church of Saints Sergius and Bacchus and was commissioned by the Emperor Justinian in 527, five years before work began on the much larger Hagia Sophia. It is one of the most important early Byzantine buildings. Its rather plain outside gives no hint to the beauty of the interior, where a two-story colonnade runs round an octagonal hall beneath an exquisite dome. The columns still retain their beautifully carved Byzantine capitals, some of them still showing off the initials of Justinian and his wife, Theodora. In the 16th century, the Church of Sts. Sergius and Bacchus was converted into a mosque and acquired not just a minaret but also a courtyard with cells opening off it, which now serve as craft workshops.

Yet another mosque worth visiting is the Atik Ali Paşa Mosque in Çemberlitaş, one of the seven hills of İstanbul. It was built by Grand Vizier Bosnalı Hadım Atik Ali Paşa in 1496, during the reign of Sultan Beyazıt II. The mosque is located near the entrance to the Kapalıçarşı (Grand Bazaar), the Column of Constantine and the historical Nuruosmaniye Mosque.

The Hırka-i Şerif Mosque in Fatih is one of the most visited mosques during Ramadan. Constructed in 1851, this mosque houses the cloak of the Prophet Muhammad (Hırka-i Şerif). The holy garment goes on display every year with the advent of the holy month of Ramadan and remains on display throughout this month. Every year thousands of people from all around Turkey flock to the mosque to see the Hırka-i Şerif.

The cloak is thought to be amongst the most authentic of items surviving from the time of the Prophet Muhammad which are believed to have been owned by him.

Many visitors fail to make it to the lovely Şehzadebaşı Mosque in Fatih, the first large-scale project of the architect Sinan, built on the orders of Süleyman the Magnificent as a memorial to his eldest son who died of smallpox at the age of 22. This beautiful mosque, which opened for prayers in 1548, was the subject of the poem “Gün doğmadan” (Before the sunrise), written by well-known Turkish poet Sezai Karakoç.

The Murat Paşa Mosque in Aksaray also deserves more attention than it receives. Built in 1473, just 20 years after the conquest of İstanbul, the mosque is squeezed into a piece of land between the tram and the metro, which means that most passers-by are in too much of a hurry to even glance at its attractive brick-and-stone-striped facade.

Also worth visiting is the Kaşgari Mosque, which is located inside the Eyüp Cemetery on the historic Pierre Loti Hill in Eyüp. The mosque was originally built as a dervish lodge (dergah) by Murteza Efendi, a Naqshbandi (a Sufi order) sheikh, who came to İstanbul in 1745 from the Chinese city of Kashgar to build this lodge after he saw it in a dream. The lodge is said to have served as the meeting place of the leaders of 12 different Sufi orders.