bastion: a strong turret or tower at the corner of a fortified building.
Walbrook: a small stream that crossed the City from north to south. It flowed near where the Mansion House now stands (Walbrook is a street at the side of the Mansion House), and fell into the Thames at Dowgate, near where Cannon Street Railway Station now stands.
Fleet River: a small stream which fell into the Thames near where Blackfriars Railway Station now stands.
Moorfields was a piece of moor land lying to the north of the City, outside the walls. The City gate which led to this district was the Moorgate, a name which still survives in Moorgate Street.
Ken Wood, in Hampstead, Hainault Forest, a small piece of wood in Essex, about eight miles north-east of London, and Epping Forest, a larger portion, also in Essex, to the west of Hainault Forest, are all remaining portions of a great forest that once stretched away from London far into the country.
Chelsea, Bermondsey: in all such words ea or ey is an old word for island. In this way are formed Winchelsea, Battersea, &c.; Thorney (where Westminster is now) is the Island of Thorns; and Jersey, Cæsar's Island.
Southwark: a district of London opposite the City, on the south side of the Thames. It was the South work, or fort, and is spoken of as a village as late as 1327, the accession of Edward III.
[2. THE FOUNDATION OF LONDON. PART II.]
Malarious: causing the air to be bad, and so giving rise to fevers; unhealthy. (Latin malus, bad; aer, air.)