Visiting Medine is highly sunnet — pray at Masjid al-Nabawi, visit the Rawdah, Masjid Quba, and Uhud; the Haramain train connects Mekke to Medine in 2-3 hours.
Visiting Medine is highly sunnet and most Hac packages include it, though it is not a ritual obligation of Hac. Hz. Peygamber (sallallahu aleyhi ve sellem) said: 'A namaz in my cami is better than a thousand namazs in any other cami except Mescid-i Haram' (Bukhari and Muslim). There is no ihram requirement for visiting Medine — you travel in your regular clothing.
Key sites to visit include: Masjid al-Nabawi for namazs and visiting the Rawdah (the area between Hz. Peygamber's pulpit and his chamber, described as a garden of Paradise), sending salutations upon Hz. Peygamber at his grave, praying at Masjid Quba (praying two rak'at there equals the reward of an Umre according to hadith), visiting the Uhud battlefield and the martyrs' cemetery, and exploring the famous date market. The Haramain high-speed train connects Mekke to Medine in about 2-3 hours and is the most comfortable option. Most hacilar spend 3-5 days in Medine.
Source: Sahih al-Bukhari; Sahih Muslim; Sunan al-Nasa'i