This guide shows how to unlock the map for Siofra River and Nokron Eternal City in Elden Ring. Map of both the areas can be unlocked by picking up a single map.
Go to Siofra River Well in Limgrave and take the elevator down to reach Siofra River Banks.
From there, go straight ahead and turn right as shown below.
Now go to the northeast corner of the area to reach an elevator near the waterfalls as shown in the picture below. Take this elevator to the upper level.
After coming out from the elevator, go straight ahead as shown below.
Soon, you will reach an area where you can see a staircase on the right side as shown in the pictures below. At the foot of the staircase, you will find a corpse with the map on it. Take this map, and this will unlock the map for both Siofra River and Nokron Eternal City.
