He drained bog land by ploughing, liming and seeding it, turning it into arable land within a few years.   He also set up a linen industry on the estate.  He built houses in the village to house the weavers and laid out the broad greens for bleaching and drying the flax.  He built a school for village children.  In another strategy to drain the land, he planted trees where Monivea Wood now stands. 
 

The ffrenchs were well respected in the county, enough so for Robert ffrench to have represented Galway in the United Kingdom parliament between 1768 and 1776. 
 
By the late 19th century the land was rich and productive, and another Robert ffrench was employing the trappings of their wealth to extend his family's high social connections, travelling overseas as a British diplomat. 
 
 

Church of Ireland, Monivea  
 
In 1759 Robert ffrench presented a memorial signed by most of the Protestant inhabitants of the village stating that Monivea was an appropriate site for a Chapel of Ease. This brand of ecclesiastical architecture is usually an ancillary church more accessible to some parishioners than the main church within the parish. They are sometimes associated with a large manor house where they provided a convenient place of worship for the family of the manor. 
The Board of First Fruits granted Robert ffrench £292 which was nearly 75% of the projected building cost and in January 1762 construction work commenced. In October 1769 the Archbishop of Tuam consecrated the church and Mr. ffrench spent £2 3s 9d on his pew. He later bought two more pews, one for the children of the Charter School and the other for his servants and tenants. By the late part of the  1700s a pulpit was installed in the church with bible, prayer books and linen.  The church testifies that by this period a large Protestant community had grown in Monivea. 

The Icehouse 
Icehouses – buildings for storing ice – can be found all over the world, dating from the earliest times.  By the mid nineteenth century, most country estates would have had at least one. 
Until refrigeration was generally available, people lived on seasonal fare with inevitable fluctuations in supply.  Food was dried, salted, pickled in vinegar or alcohol, smoked, parboiled, potted or kept in sugar syrup.  Greater variety was available only to the rich who had living supplies in the dovecote, deer-park, fishpond and rabbit warren.  The wealthy supplemented that fare through the use of an icehouse, regarded as a luxury in the eighteenth century. 
In 1786 an icehouse at Inberaray, Strathclyde, was constructed in four months and cost £25.  By this time, not only were new construction methods being used but there was also a new appreciation of the potential for food storage offered by the icehouse as demonstrated by the architect, John Papworth:  “the icehouse forms an excellent larder for the preservation of every kind of food liable to be injured in the heat in summer; thus fish, game, poultry, butter, etc., may be kept for a considerable time”. 
Ice was collected from natural or artificial freezing ponds on the estate.  Efforts were made to keep the freezing pond as clean and clear as possible, sometimes posting a gamekeeper there to move twigs and scare away birds and mammals.  A head gardener and writer, Charles MacIntosh describes filling an icehouse: “the ice should be broken with mallets or stampers to a coarse powder and well rammed down in the well or pit, keeping the upper surface concave and adding a little water from time to time in order to fill up the interstices and assist the congelation of the whole into a solid mass”. 
Icehouses continues in general use until the end of the nineteenth century.   With the decline of country estates after the First World War, icehouses increasingly fell into disuse and overgrown examples were often rediscovered only by chance. 
The icehouse in Monivea Demesne was constructed by the ffrench family to serve the castle.  The chamber reaches several metres underground and is well insulted at the top with stone and earth, thus enabling food to be kept cool in the hottest weather.  The shelter of the surrounding trees would also have helped to keep the temperature of the contents down.  This might explain the distance between the icehouse and the castle, which would surely have created extra work for the castle servants. 
The entrance was repaired in 2000 and a grille installed for the safety of the public.