Shangri-La was a village located in what was called the Valley of Lies. It was a haven for those with bounties on their heads who wanted to live their lives without worrying about being pursued by bounty hunters. To achieve this, villagers used the Transformation Technique to change their appearance and avoided thinking about or even discussing the past. There were few villagers that everyone knew everyone else, a useful way of identifying visitors and therefore possible threats, but nobody knew what anyone looked like without the Henge.
This small village was also built to avoid notice. It was built in a cave in the side of a mountain, the village's structure being carved from the mountain itself. Said cave has been expanded in order to accommodate the village, a large tree was planted in its center to support the mountain's weight. No roads led to the village in order to avoid attention, meaning villagers had to scale the mountain on their own. A nearby river created a natural aroma throughout the area that the villagers used as a medium for genjutsu, rendering Shangri-la invisible to anyone affected by it. The genjutsu was quite complicated, requiring that several villagers constantly weave the hands seals needed to maintain it.
Unfortunately for them, in this timeline, the Hokage took particularly care of finding small information like that to ȧssure that Minato would not die easily. Even if he said to him that without adversities, he will not progress, he gave his all to minimize the risk and control said adversities. Minato was a one in a hundred years genius, if he was killed, it would be an immense loss to Konoha.
It's then that he discovered the existence of Shangri-La, and because of the unusual movements of some of Konoha troops, Suna also discovered it, making this small village a hidden battlefield for the war. The side which can control those people could earn a small advantage. Even if it isn't much, a small advantage is still an advantage.
Some days ago, a Konoha spy that infiltrate the village was caught writing a report and killed on the spot by the villagers. Hiruzen would have sent another spy or even annihilate this small village but decided that this place was a good training ground for Minato, so he sent him there in order for him to learn infiltration and information gathering directly from experience. With Minato not using a Henge, people will drop their guards around him making the experience a bit easier. And from the intel he gathered, nobody there could kill Minato without giving him a chance to escape. Of course, he has chances to be killed if he is careless, but he was not willing to have a sheltered successor. If he died, it means that he was not fit to become Hokage.
And so, Jiraya dropped Minato near the area and went by on his way to accomplish another mission in the Land of River, promising him to come back one week later to collect the information that Minato gathered. As for the genjutsu? He knew that Minato could easily see through it, and how to enter without appearing suspicious will be to his discretion. He already taught him all he needs to know for this mission during the mission to the Land of Rock, even how to suppress his chakra, so all the cards are now in his hands. Still, he has great confidence in his disciple.
Looking at the departing Jiraya, Minato smiled and stretched. He was finally alone, with nobody watching him. Even if he became used to it, it took a toll on him to control what he says and how he acts to not cast suspicions on him. Even if he has Minato's memories, he still has some mannerism from his time as Byron so it's not so easy to act like a quick-witted child around others.
'But how to enter the village without appearing suspicious' He mulled for a plan, and looking at the clouds gathered in the sky, indicating that it will soon rain, a light bulb went up to his head.
"It will soon rain so it's basic common sense to look for a shelter, and what better one than a cave"
He then stored all his shinobi possessions in his lotus seal, while everything else was stored into his backpack.
Going into the direction of the mountain, he arrived at the foot of it in a matter of minutes. When he reached there, he sensed some gazes on him with his Hyper Intuition, but could not pinpoint their exact locations with his chakra sense, because of the Genjutsu interference.
He walked along the mountain, acting like he was a kid whose village suffered some calamities and was currently traveling, looking for a cave to take shelter from the rain. In no time at all, his Hyper Intuition flared up, indicating what he was looking for. He then activated his Sharingan and casually swept up the mountain with a look, without pausing even when he saw the Genjutsu array.
To the villagers at the entrance on Genjutsu's duty, it looks like Minato was looking around the mountain. Nobody would ever suspect that this kid has the fable Sharingan, able to see through the flow of chakra.
Acting like he was tired of looking around, Minato then went on climbing the mountain, activating the resistance seal at the same time to make the act more believable, with the sweat beginning to build upon his forehead.
From the foot of the mountain, people would have a hard time seeing everything, so Minato's actions were believable. And so, when after fifteen minutes of looking around Minato stumbled upon the hidden cave, the guards were not suspecting anything at all taking Minato for a lucky kid having discovered the entrance to their villages by chance.