The Prophet on Yawm Nahr (10 Zul Hijjah, day 3) travelled from Muzdalifah to the Jamarat (Mina). He pelted Jamarah Aqabah, then slaughtered animals, and then shaved his head. Thereafter, he travelled to Makkah to do Tawaf Ziyarah.
The walking distance from Arafat to Makkah is 21 km. From Muzdalifah to Mina is 7-10 km. From Mina to Makkah is 6-7 km if you go straight but if you take the route to Makkah via the tunnel through the mountain on the left just after Jamarat it is 4 km.
Standard route to Makkah
The standard route is to travel around the mountain. Jamarat to Makkah is around 6 km. It is hot and long. It is the route the Prophet (peace be upon him) took. Is it a separate act of worship to take this route? The Sahabah and ulama are disputed.
The shortcut to Makkah
The new route through the mountain. Jamarat to Makkah is around 4 km. It congested when taking left straight after Jamarat but then it eases. The tunnel is cool and compared to the standard route it is faster.