Access by train from Chamonix. This is free if you have a guest card, which can be obtained from the Chamonix Tourist Office: price €10. Get off two stops later at Les Tines station.
(S/E) When leaving the station, cross the road carefullyand turn left for about 100 metres. Then turn right onto the small tarmac road, following the sign for "Le Chapeau".
(1) After about 200 metres, turn left onto the steep path and follow it to the chalets of Hameau d'en Haut.
(2) Follow the road to the right for a few metres, then turn right again to rejoin the path towards Le Chapeau.
(3) Leave the Grand Balcon Nord trail on your left and continue straight ahead to reach the Torrent du Chapeau and its waterfall.
(4) Cross the torrent and continue to the refreshment bar (terrace and viewpoint).
(5) Continue right (south-east) along the path to reach the viewpoint over the Mer de Glace.
(6) Turn back and follow the route uphill in the opposite direction to return to Les Tines station (S/E).