Built by Lord Andrew Thomas Blayney in the 1780's near the original castle, no longer extant, the building was refaced and embellished during the 1860's by Henry Thomas Hope. The entrance porch and canopy date from this as does the nearby Coach House or Annex.
The Castle was the home to the Duke of Connaught (son of Queen Victoria) and his family for 4 years and later served as a military barracks during the War of Independence (1919-21). It was the site of Monaghan Co. Hospital 1932-37 and served as a Franciscan Order from 1942 until the early 1970's.
After this period The Hope Castle fell into private ownership and then in the 1980s was acquired by Monaghan County Council. The building was later sub-let under a County Council lease and while under this lease in 2010 was extensively damaged in an arson attack the building remains in a non used state at this present date.
The Market House
The Court House has often been described as an interesting and puzzling building. There was a market house on the site as early as 1801. A new courthouse was built in 1856. The upper part of the existing building looks Victorian but the bottom storey looks much older. From this it would seem that the new Court House was built on top of the old Market House.
The Market house which is the property of Monaghan County Council was up until the 1990’s home to Castleblayney Court Services and also the town Library, however during the latter period of the 1990’s the building reached a state of disrepair and now remains in a derelict and dangerous state and unoccupied.
A most impressive display of continental design in a row of 7 houses built in 1877 for the labourers on the Hope Estate. The design is reputed to be of French origin.
St. Maoldoid's Church (C.O.I)
The Church of Ireland was rebuilt in 1808 on the site of an older church. A spire of 36 metres was added in 1818 and a gallery built. The church was further extended in 1829 when Lady Blayney presented stained glass windows.
The Blayney Vault
Situated in the cemetery of St Maoldoids Church, they contain the remains of a number of Blayney family members. Lord William, the 6th Lord Blayney was the first family member to be buried in the vaults. He died on January 3rd, 1706. The 11th Lord, Andrew Thomas, is buried in a separate vault nearby.
The Alms House
When the 12th Lord Blayney died in 1874 he left money for the setting up of the Alms Houses. Built of red brick, the building is made up of twenty apartments with bed-sitter and a small scullery. In the grounds are a lodge and a memorial in memory of Cadawalladar the 12th and last Lord Blayney.
Pigots Directory of 1824 lists the "The Blayney Arms" owned by Wm Twibill, as one of two hotels in the town. This is now known as "Hope Arms" and situated directly opposite the entrance to Hope Castle. One of its most famous patrons was Charles Stewart Parnell, who stayed there on the night before polling in a famous Monaghan By-Election in 1883. Parnell refused to sleep in room No. 13, but his candidate, Tim Healy did and subsequently won the By-Election.
Mc Mahon's Castle and the Temple of Concra
The ruins known locally as Mc Mahons Castle, off the Dundalk Road, on the south of Lough Muckno, has puzzled many scholars and historians. It even gave its name to an old and now disused name of the town: Caislean Mhathunach. The Mc Mahons of Gaelic rule in Ulster had no Castle in the Castleblayney area.
The Temple also at Concra, which has now fallen into disrepair and would appear to be of Greek design, was a resting/summer house for the Blayneys and the Hopes.
St. Mary's Hospital
Built in 1840-42 under the direction of the Poor Law Guardians, this building was one of four workhouses in Co. Monaghan and its history has been fairly well documented. The years of the Famine were the most traumatic, for the workhouses. In March 1849 there were 1,850 inmates and disease was rampant. For many, the only relief was either death or emigration. Many of those who died were buried in the graveyard beside the hospital, known today as the "Garden of Remembrance". In 1926 it became the County Home, being extended and extensively renovated in 1969 when it was restyled as St Mary's Hospital.
Convent of Mercy
The Sisters of Mercy came to Castleblayney in 1905 and opened a school in New Street, but the story of the present site of the Convent is a much older one. It was formally the site of the thriving brewery, lending its name to the old name of the location - Brewery Hill. In 1767 it was owned by a Mr Lewen. He sold the site to Captain Henry, agent to the 10th Lord Blayney. Capt. Henry's granddaughter married a Dr Gillmour and the site remained in her possession until 1903 when Canon Meegan, P.P., purchased it for the Sisters of Mercy. The foundation stone of the Convent was laid on August 31, 1910. The building was designed by G.G Mc Donnell, architects, Belfast.
The Dundalk-Enniskillen Railway line reached Castleblayney on February 15, 1849. The railway station at New Street was situated on ground leased from Lord Blayney. Sadly, the railway is no longer a feature of life in Blayney. The last train left the town on October 10, 1957.
Presbyterian Church, Lakeview
Built in 1788 on the plot of land donated by Lord Blayney for "a place of worship for the Dissenters" on his estate. Very neat, a simple meeting house style.
In the townland of Churchill, to the north east of the town, is the site of the old monastery church and graveyard. The Monastery Church became the Parish Church of Muckno during the middle ages. The graveyard was used in living memory but has fallen into a very neglected state. At the turn of the century the Duke of Connaughts daughter paid a visit to Mullandoy and stuck two large pins into a tree and made two wishes. This tree became the wishing tree and the girl who "began" it later became the Queen of Sweden.