On Sammed Shikharji (Śrī Sammed Śikhar), according to Jain tradition, 20 out of 24 Tirthankaras attained Nirvan (moksha).

Those 20 Tirthankaras are:

1. Ajitnath (2nd)
2. Sambhavnath (3rd)
3. Abhinandannath (4th)
4. Sumatinath (5th)
5. Padmaprabhu (6th)
6. Suparshvanath (7th)
7. Chandraprabhu (8th)
8. Pushpadant / Suvidhinath (9th)
9. Sheetalnath (10th)
10. Shreyansnath (11th)
11. Vimalnath (13th)
12. Anantnath (14th)
13. Dharmanath (15th)
14. Shantinath (16th)
15. Kunthunath (17th)
16. Aranath (18th)
17. Mallinath (19th)
18. Munisuvratnath (20th)
19. Naminath (21st)
20. Parshvanath (23rd)

The remaining 4 Tirthankaras attained Nirvan at other places:

• Rishabhdev (Adinath) – Aṣṭāpād
• Vasupujya – Champapuri
• Neminath – Girnar
• Mahavira – Pavapuri

Both Śvetāmbara and Digambara traditions agree that Sammed Shikharji is the Nirvan-bhumi of these 20 Tirthankaras, along with countless munis and sadhus.

You can read a simple explanation about Sammed Shikharji here: “Mysterious of Shikharji temple”