The site of a night watch beacon at Poolvaaish dating to 1627 (and probably earlier). It is commemorated by the name Cronk y Watch (on the 1957 Ordnance Survey 6 inch map). It shown as 'Polbash' on a map with an official document dated 1627. The watch system, which apparently derives from the Norwegian period, was founded on a chain of vantage points around the island, two at least in every parish, upon which beacons were prepared. There is written evidence, as early as the 1490s, that every parish kept both Day and Night watches.

This stone was found, broken in two, during excavation at Cronk yn How (IOMHER 0468.00) in 1928. When the two pieces are laid together, a cross formed by a clearly cut vertical line, to which a horizontal line has been added by several lighter scratches, can be seen.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. One face of this broken slab bears a simple form of linear cross, with irregularly cut lines.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. On one face it bears a feebly-cut cross, with fine scratches showing initial practice strokes.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. It is a narrow, broken slab, bearing a cross formed by finely-scratched lines, on one face.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. This narrow slab, with its end pointed for setting in the ground, bears a simple cross with lines punched by a pointed chisel.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. The slab is broken and flaked, but shows the remains of a plain cross in outline, and other scratches.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. Only a broken and damaged fragment survives, with a plain cross in outline, formed with very fine lines. There are slight remains of a chevron design below.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. On one face the slab bears a feebly-drawn cross set at an angle. There is a slight attempt at framing the cross.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. This broken slab has been carved on both faces. One face bears a linear cross finely cut with the point of a knife; the horizontal bar, represented by two strokes, marks the beginnings of a panel over the head of the cross. A well-cut hexafoil cross set within a circle is drawn in the middle of the other face. To this, another hand has added an irregularly-drawn outer border. Above is a small plain cross in outline. An irregular linear frame has been added inside the edge of the slab, which has been overscored with another frame of zig-zag scratches.

This fragment of stone, just 0.23m long, was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. One edge bears a fragment of a runic inscription, the letters of which do not survive to full height. The stone went missing from the church during the 1990s, but a cast remains in the collections of Manx National Heritage.

This stone was found during excavation at Cronk yn How (IOMHER 0468.00) in 1928. The face and any carving appears to have flaked off. It was identified as a grave marker on the strength of its deliberately rounded head.

Dr G. Bersu was convinced that the Cronk yn Howe keeill was built upon a Viking burial mound and that it cut through the ship, evidence of which is provided by the presence of Viking ship clinch nails.  Evidence for a Viking boat-burial at Cronk yn How is so fragmentary, however, that Bersu's conjecture has been disregarded by later archaeologists.

The site of the burial ground associated with an early medieval keeill or chapel which would have been in use between circa AD500 and AD1000.  Cronk yn How was excavated by J.R. Bruce and W. Cubbon in 1928.    The area bears evidence of occupation from the Neolithic period onwards, but the mound was built in the 7th-8th century for a keeill. Subsequently a stone building, measuring 6 metres by 2.4 metres, was built. It appears to have been an oratory chapel with associated burials of Irish type, tentatively assigned to the 12th century.  The position of the keeill was shown by the occurrence of lintel graves and cross-slabs. Ten cross-slabs were found dating to the 7-8th centuries. Many were associated with burials, and three others were incorporated in the later building.  Not all the burials in the keeill graveyard were of the lintel type. One belonging to the end of the keeill period had an iron knife and 'button' associated with it. Another, possibly a pagan Scandanavian burial with covering slabs, passed beneath the stone building foundations. There was a horse burial on the west side of the mound, represented by the fragmentary remains, but no dating evidence. Iron nails and rivets apparently associated with the burials were of typical 'Viking' date, as were a green glass bead and fragment of a rune-inscribed standing cross also found at this site.

The site of the mound raised before the construction of  an early medieval keeill or chapel which would have been in use between circa AD500 and AD1000.  Cronk yn How was excavated by J.R. Bruce and W. Cubbon in 1928.    The area bears evidence of occupation from the Neolithic period onwards, but the mound was built in the 7th-8th century for a keeill. Subsequently a stone building, measuring 6 metres by 2.4 metres, was built. It appears to have been an oratory chapel with associate burials of Irish type, tentatively assigned to the 12th century. It is possible that the mound under the keeill was originally a prehistoric barrow.

A fragment of a cross-incised stone was found here in 1928. It measures 26.7 centimetres x 33 centimetres x 3.2 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A fragment of a cross-slab with a hexafoil cross incised on one side and a plain cross on the other side, found here in 1928. It measures 56 centimetres x 30.5 centimetres x 2.5 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A fragment of a Runic inscribed cross-slab, found here in 1928. It measures 23 centimetres x 5.7 centimetres x 3.8 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A fragment of a cross-incised stone was found here in 1928. It measures 39.4 centimetres x 20.3 centimetres x 3.2 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A fragment of a cross inscribed slab, found here in 1928. It measured 67.3 centimetres x 20.3 centimetres x 2 centimetres. It is now lost.

A slate slab with a rounded head, the face of which had flaked off, found here in 1928. It measured 73.7 centimetres x 33 centimetres x 5 centimetres. It is now lost.

A cross-incised stone was found here in 1928. It measures 40.5 centimetres x 22 centimetres x 2 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A cross-incised stone was found here in 1928. It measures 51 centimetres x 19.5 centimetres x 3.2 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A cross-incised stone was found here in 1928. It measures 61 centimetres x 14.5 centimetres x 5 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.

A cross-incised stone was found here in 1928. It measures 75 centimetres x 17.8 centimetres x 5.7 centimetres. It is one of several cross slabs which were moved and kept at Lezayre parish church.