I’ve done both the Manali–Leh and the Srinagar–Leh routes, and honestly each one feels like a completely different adventure.
On the Manali–Leh side, the thrill is in the sheer ruggedness. You’re crossing some of the world’s highest passes (Rohtang, Baralacha La, Tanglang La), riding through stark mountain deserts, and passing surreal spots like Sarchu and Pang. The landscape changes almost every few hours – from lush valleys to barren moonscapes. It definitely feels more “adventurous” because of the tougher roads and higher altitude. You’ll also find hidden gems like Suraj Tal (a beautiful high-altitude lake) that often get missed. But be ready for long stretches without much habitation.
The Srinagar–Leh route, on the other hand, is less harsh on your body and bike/car, but offers more cultural and historical stops along the way. Sonamarg is gorgeous, Zoji La pass is dramatic, and the drive through Drass (the second coldest inhabited place on Earth) and Kargil makes it feel very special. You’ll also get to visit monasteries like Lamayuru, which is one of the oldest in Ladakh. For many, this route feels more scenic in a “green mountains giving way to barren Ladakh” sort of way.
If you’re asking purely about adventure, I’d say Manali–Leh is the rougher, wilder experience. If you’re looking for a blend of history, culture, and gentler acclimatization, Srinagar–Leh is a better pick. A lot of travellers actually do one route up and the other route down to experience both sides – and that’s what I’d recommend if you have the time.