We've perfected many technologies over the years that allow us to travel to almost any point at all on, over, or even under the earth. Everest is getting old. Even space tourism is quickly moving from science fiction to marketing hype.
The real challenges that are left to us start when we want to travel nowhere; when we are our own destination.
It's not just an imaginary intellectual journey. Even drugs (no matter the potency or effect) are of little aid. When we are told it's not enough to learn something and know it, it has to pierce to your heart, it needs to change you. (As the Mei Shiloah and Bilvavi Mishkan Evneh explain) It means you need to gain real and true intimate knowledge of your soul.
The same way you know what your best friend or spouse is thinking and how they will react to a particular experience, you need to reach that level of relationship with your soul.
Even in the Baal Shem Tov's metaphor, [see: parable of the baal shem tov] the motion seems external, we are trying to surmount impregnable walls, to circumvent fierce creatures. If I say, well now, what do I do with this metaphor, how do I internalize it? I need to somehow change my perspective, my gaze, and focus it inwards. I need to travel without moving.
Well, it isn't exactly without moving. I can (and still need to) move around in the three (plus one) dimensions I'm familiar with. How else will I do mitzwoth and learn Torah? But my progress inward isn't directly related to any motion in those other media.
This is the part where it's just you and HaShem. (You can and certainly should ask a Rebbe to help you in this journey, but tachlis, at the end of the day, it's just you and HaShem.)
The beauty of this relationship is, the more room you make for HaShem, the more HaShem is present, the more you can get in touch with the root of who you are and the less veils stand between you and the King.
There're no rules beyond that. The more you invest mitzwoth and Torah with holiness, every simple action with awareness of HaShem, the further each step in this world takes you inside.
The smallest movement, the smallest action out here, can pierce you to your deepest.