Baab-As-Salaam (Arabic باب السلام), pronounced as "bāb assalām", is one of the gates at the Masjid-al-Haram at Makkah-Al-Mukkarammah. This phrase in Arabic when literally translated into English means "Gate of Peace". It has been a tradition for first time visitors to the mosques to enter the Masjid-al-Haram through this gate.
This gate is located in the stretch between Mount Safa and Marwaah.
References
Baab-al-Salaam Wikipedia(Text) CC BY-SA