These were availed of for the monasteries of the Fenland--Ely, Peterborough, Crowland, and others, all established by the Benedictines. The abbey of Bury St. Edmunds, although situated some distance from the marshland, may also be classed among the religious houses of the Fens. This abbey, which is a short distance east of Cambridge, was built in the eleventh century as the shrine of St. Edmund, King of East Anglia, who was killed by the Danes about the year 870. It soon became one of the wealthiest English monasteries, and was the chief religious centre of that section. Only ruins remain, the chief being the abbey-gate, now the property of the Marquis of Bristol, and the Norman tower and church, which have recently been restored. In the suburbs of Bury is Hengrave Hall, one of the most interesting Tudor mansions remaining in the kingdom. Originally, it was three times its present size, and was built by Sir Thomas Kytson about 1525. Its gate-house is rich in details, and the many windows and projections of the southern front group picturesquely. [Illustration: ELY CATHEDRAL, FROM THE RAILWAY-BRIDGE.] Following the Cam northward from Cambridge through the marshland, we come to the Isle of Ely, the great "fortress of the Fens," and standing upon its highest ground the cathedral of Ely. Here St. Etheldreda founded a monastery in the seventh century, which ultimately became a cathedral, Ely having been given a bishop in 1109. The present buildings date all the way from the eleventh to the sixteenth century, so that they give specimens of all Gothic styles. The cathedral is five hundred and thirty-seven feet long, and from the summit of its western tower can be gained a fine view of the spreading fens and lowlands of Cambridgeshire, amid which stands the Isle of Ely. One of the finest views of this tower is that obtained from the road leading to Ely Close. Before drainage had improved the surrounding country this was one of the strongest fortresses in England, and it was also one of the last to yield to the Norman Conquest, its reduction causing King William heavy loss. Afterwards he regarded it as among his most loyal strongholds. The lofty tower, and indeed the whole cathedral, are landmarks for the entire country round, and from the rising ground at Cambridge, fully twenty miles to the southward, can be seen standing out against the sky. From the dykes and fields and meadows that have replaced the marshes along the Cam and Ouse the huge tower can be seen looming up in stately grandeur. It is almost the sole attraction of the sleepy little country town. The great feature of this massive cathedral is the wonderful central octagon, with its dome-like roof crowned by a lofty lantern, which is said to be the only Gothic dome of its kind in existence in England or France. We are told that the original cathedral had a central tower, which for some time showed signs of instability, until on one