This is a view of Muzdalifah, where Hajj pilgrims arrive after sunset from Arafat on the 9th Dhul Hijjah (second day of Hajj).
Muzdalifah stretches from the Valley of Muhassar to the mountains of Ma’zamayn. It is four kilometres long and covers an area of 12.25 square kilometers. Referring to Muzalifah, Allah (ﷻ) mentions in Surah Baqarah in the Quran: “When you leave Arafat, then remember Allah at the Mash’arul Haram.” (‘The Sacred Monument’, referring to Muzdalifah according to Abdullah bin Umar (may Allah be pleased with him)
During the farewell Hajj, the Prophet (ﷺ) performed the Maghrib and Isha salats together at Muzdalifah. He stayed at the spot where the present Masjid Mash’arul Haram currently is (towards the Qibla side). From there, the Prophet (ﷺ) said: “Although I am staying here, you may stay anywhere throughout Muzdalifah.” [Muslim]
During Hajj It is waajib to perform Maghrib and Isha together in Muzdalifah at Isha time. Wuqoof (stay) of Muzdalifah is also waajib and it’s time begins from sub’h saadiq and ends at sunrise. If one spent even a little portion of their time in Muzdalifah, he/she will be absolved of this obligation. However, it is best to remain until just before sunrise. Although pebbles for pelting the Jamarat may be collected from anywhere, they are best collected from Muzdalifah. Muzdalifah is also called ‘Jam’ as it is a place where people gather.
Source: Islamic Landmarks