Baab ur Rayyan
Baab ur Rayyan or Baabur Riyyan is the name of gate of paradise for the ones who fast during Ramazaan.
It could be noticed that the name of the gate Al-Rayyan means in Arabic 'whose thirst is quenched' corresponds to the characteristic of the person observing fast who suffers thirst as the effect of fasting. Paradise does not have only one gate, rather it has many gates. 
Allaah says (interpretation of the meaning): “And those who kept their duty to their Lord (Al-Muttaqoon – the pious) will be led to Paradise in groups till when they reach it, and its gates will be opened (before their arrival for their reception) and its keepers will say: Salaamun ‘Alaykum (peace be upon you)! You have done well, so enter here to abide therein” Surah al-Zumar 39:73
Allaah has promised those who fast, namely the gate of al-Rayyaan. This is the name which was narrated in the hadeeth whose authenticity is agreed upon. Sahl (R) said that the Prophet ﷺsaid: “In Paradise there is a gate called al-Rayyaan, through which those who used to fast will enter on the Day of Resurrection, and no one but they will enter it. It will be said, ‘Where are those who fasted?’ They will get up, and none will enter it but them. When they have entered, it will be locked, and no one else will enter.” Sahih al-Bukhari, 1763; Sahih Muslim, 1947
Jannah has eight days. In the saheeh ahaadeeth it says that: It was narrated from Sahl ibn Sa’d (R) that the Prophet ﷺsaid: “In Paradise there are eight gates, among which is a gate called al-Rayyaan, which none will enter but those who fast.” Sahih al-Bukhari, 3017.