This is a club, which means that the bar may be only open to members.
There are three large, comfortable rooms and a "clubby" atmosphere. Regimental plaques and military paintings adorn the walls and there is even a proper pub sign!
Although parts of the Royal Hospital (in which the Club stands) are open to the public - and a visit to this Wren-designed complex is recommended - the Club is open only to Chelsea Pensioners and their guests; CPs get discounted prices.
Note the unusual (unique?) double-slotted pillar box at the London Gate.
Chelsea Pensioners' Club, Chelsea