General
The Slytherin Blocs is a small and accessible area (from the drop off point) that is home to a number of fine low- to mid-grade problems. The northerly aspect and ease of access makes it a good spot for a quick afternoon session.
Access
The Slytherin Blocs are located on the northern side of Kai Kung Leng, near the Ngau Tam Mei Fresh Water Service Reservoir. Access will require either a taxi ride or a car to get you to the bend in the road / stream just east of the Ngau Tam Mei Service Reservoir (22.468633, 114.074353). From the small clearing, follow the slope maintenance staircase to the left of the stream (looking up hill)a short way before breaking left along a berm. This will bring you to a dirt trail that weaves up the hill to eventually reach a small outcrop. Follow the trail right at this point and scramble over and around some blocs to reach the bouldering area itself. The approach takes less than 10 minutes from the road.
Blocs
Basilisk
The first major bloc reached is a gravity defying boulder housing two lines, one of which is a rather serious proposition requiring a very steady head.
1) Basilisk ** V5
A pulse raising excursion up the main face of the bloc. From pockets above the ledge, step left above the drop and keep moving up and left across the face with increasing trepidation.
2) Nagini V2
Start at the same spot as Basilisk but take the more sensible direct approach up the face above. Just be careful not to bounce off left if you fall!
The Wall beneath the Basilisk overhang also appears to have potential for a few lines for those willing to spend some time clearing and cleaning it a bit.
Quidditch
Just around the corner from the Bailisk is a tall slabby face with a number of pleasant highball slab climbs on it.
1) Invisibility Cloak * V1
Follow the pockets up the left side of the slab, trending behind the tree and being
hidden by the bushes.
2) The Golden Snitch * V1
Another pocketed line, this time taking the slab just to the left of the crack splitting the upper part of the face.
3) Quaffle * V1
Start directly beneath the crack and climb up to, and then follow, this.
4) Nimbus 2000 ** V2
Follow the pockets up the wall to the right of the hanging crack, passing through the overlap just to the right of the v-shape.
5) Holyhead Harpies ** V1
Climb the right side of the slabby face.
Snitch
Just up the hill from the Quidditch Bloc is another slab with a couple of easy lines.
1) Snidget * VB
The left side of the slab, following a series of large incut pockets.
2) Seeker * VB
The right side of the slab, starting at the large flake.
Spell Bloc
Continuing up the trail a short distance from Snitch Slab, and bearing slightly left brings you to a large opening in the vegetation and a cluster of several quality blocs. The most prominent of these is the long face of the Spell Bloc
1) Sectumsempra (sds) * V4
Start on small pockets low on the left side of the face. Make a tendon wrenching pull to get started and then follow much nicer pockets up the wall above.
2) Stupefy (sds) * V1
Sit start at a low deep pocket. Make a powerful pull to good crimps and then follow the deep pockets above.
3) Obliviate * V1
Start at a low lay away. Pull up to the left side of the ledge above and then continue up positive pockets.
4) Crucio * V2
Start at the low ledge on the right side of the wall. Pull up and left to the right side of the higher ledge, before continuing directly up this via small crimps and pockets.
5) Cunfundo ** V1
Start as for Crucio, but this time keep working your way left across the wall to eventually join and finish up Stupefy.
6) Avada Kedavra * V2
Sit start at the same ledge as the previous problems. From here, crank directly up to climb the wall above via an assortment of crimps and pockets.
7) Smoothie Power (sds) ** V4
From the low ledge on the right side of the wall, make a low level traverse right to gain a gaston in a positive pocket at the arête. Move powerfully from this to gain more pockets above and an easier finish.
8) Patronum (sds) ** V2
Start using the low pocket beneath the gaston on Smoothie Power and an even lower pocket out right. Use these to get established on the face and to join the upper part of Smoothie Power.
Sirius Bloc
Sandwiched between the Spell Bloc and Horcrux Bloc, this boulder provides some of the harder test pieces in the Slytherin Sector.
1) Fire Ant Straight (sds) V6
Start at a positive layaway low on the left side of the face. Figure out how to get established without dabbing the boulder to the left or the tree stump, then attack the wall directly above with difficulty.
2) Fire Ant (sds) * V7
Start as for the previous problem, but rather than just topping out, traverse right using pockets and crimps beneath the lip to eventually top out at the right arête.
3) Black Magic (sds) V8
From the same start as the previous problems, make a low right traverse across the face to gain the thin undercut flake, which is followed upwards. Be gentle with the flakes as they may not last that long given their hollow sound.
4) Azkaban *** V5
Start on small crimps on the left side of the face. Reach up to a small pocket and then make a long move to the lip above.
5) Azkaban (sds) ** V7
The sit start to Azkaban, moving into the original line from tiny crimps and pebbles low on the right side of the face. For an extra bit of difficulty and a V8 tick, start matched on the right hold by the arête.
6) Goblet of Fire ** V5
From opposing sidepulls either side of the arête, slap your way up the narrow prow.
7) Dementor (sds) ** V3
Sit start at the positive pockets right of the arête. Pull up to the shelf above and then traverse this left to eventually move around the arête and on to the Azkaban face. Rock over the lip to finish.
8) Muggle Struggle (sds) * V2
Start as for Dementor. Reach up to the sloping shelf directly above and then continue through this to top out.
Horcrux Bloc
The bloc immediately to the left of the Sirius Bloc has a fun narrow end face as well as a slabby side face with several quality lines
1) Salazar * V1
Tackle the left side of the slab, starting at the sloping ledge and making use of a deep pocket to enable a long reach for the positive lip above.
2) Cerberus * V3
The right side of the slab is a slightly more testing affair, yielding to balance, crimping and rock overs.
3) Horcrux * V1
The right arête of the slabby face of the bloc.
4) Two Faced Professor (sds) ** V1
Sit start using a positive lay away with the right and low pocket with the left. Make use of further positive side pulls to work your way up the narrow face to positive jugs at its lip.