The existence of Brumer-Stark unit is guaranteed by the Brumer-Stark conjecture. A conjecture of Dasgupta gives an explicit p-adic analytic formula for these units. An approach to this explicit formula is given by the tower of fields conjecture of Gross. After recalling these conjecture and relationship between them, I will sketch a proof the tower of fields conjecture. This is a joint work with Samit Dasgupta.