After you gain the power to open the door inside the Temple of Time, you can descend to the kingdom of Hyrule.
From the Temple of Time
After you complete the Nachoyah Shrine you can descend to Hyrule from the Temple of Time. As you fall, hold R and make sure you are positioned over the water.
Swim northwest toward the glowing waypoint on the map. You may see a glowing object fall from the sky up ahead. Objects that fall from the sky can be moved around with Ultrahand and reversed with Recall. You can even fuse them to your weapons.
Keep going northwest and you will see a Bokoblin. If you crouch, you should be able to sneak up on it and perform a Sneakstrike when you get close. Otherwise, defeat it, then take the apples that it was carrying.
Nearby, there is a pile of construction materials. Read the sign if you wish. Go north along the path next to the construction materials. You will see a camp of Bokoblins on the left, but they aren't guarding any treasure except for a Sundelion that you can gather.
Farther along the path, there is another pile of construction materials, and the path splits. Go along the west path and you will find the remains of a ranch, with some Bokoblins wandering around. Go to the west side of the ranch and look north to see a cave. This is Ranch Ruins Cave.
Go to the Destination
From the northern opening of Ranch Ruins Cave, go north and you will find a stone roadway. Go north along this road, and there is a Bokoblin camp to the right. Defeat them or sneak past, then continue along the road.
Eventually, you reach a crossroads. Take the west path, and you will reach Lookout Landing.