Sasso di Sesto/Sextner Stein is pretty much a backyard rock of the refuge Rifugio Locatelli/Dreizinnenhütte.
It is located slightly northeast of the well known Dolomite postcard, namely the Three Lavaredo tops. Once visitors, especially first time visitors, somehow manage to detach their eyes from the Tre cime di Lavaredo/Drei  Zinnen walls, next step is to ascend something and enjoy better views with less crowd around. This is where Sasso di Sesto comes handy. Unmarked (at a time of visit), yet clearly visible path  circumvents it's southeast flank leading to the small col where one may make a decision, either go up right and up the ferrata routes of  Torre Toblin, or  less demanding ascend of Sasso di Sesto.The later, with 50 minutes of time required and 101 metres/331 feets of altitude difference from Forcella di Toblìn/Toblinger scharte, it is arguably the easiest ascend in the Lavaredo rim of climbing routes.
Once at the top, you'll notice three things;
- excellent panorama views,
- fact that it is a standalone rock (from some angles Sasso di Sesto does appear glued together with Torre Toblin),
- sad remains of the World War I. Sasso di Sesto/Sextner Stein was an Italian army outpost,
nearby Torre Toblin joined the Austrian army and completed his service as an observation point for the Austrian artillery.

It is a bit odd in it's own way to visit the whole area decades later as a tourist. But tourists are always welcomed,
and properly charged.

1.  By car from the north, over the Brenner/Brennero pass down the main road for Bolzano/Bozen, exit Bressanone/Brixen and drive for Brunico/Bruneck. From Brunico/Brunneck continue direction Dobbiaco/Toblach via Vilabassa/Niederdorf, from  Dobbiaco/Toblach  via Val di Landro/Hohleinsteintal road no. 51., pass the Durrensee lake, take off at  Schluderbach and follow road 48b till the Misurina lake. From Misurina lake, we have two options, less scenic, quicker and more expensive is to drive all the way to the Auronzo  hut parking lot (road toll).
   More scenic and time consuming is to leave the car at the lake. At the eastern side of the Misurina lake, pass the Misurina camping site and follow the walking path for Rifugio Lago d'Antorno hut located on  the left bank  of the Lago d' Antorno lake. From here, round two and half  hours  of footwork takes us to the Forcella Longeres and the Auronzo hut parking lot. Path  is marked no. 117 and  it is a part of the Sentiero Bonacossa trail.
2. 
   From the South, drive for Cortina d' Ampezzo, at Cortina fork right and take road no. 48, at next junction leave 48
   and fork left for 48b and  further till  the Misurina lake.
   
   From the East, classic gateway via Lienz in Austrian Carinthia, at  Innichen/S.Candido fork left for Sexten/Sesto (7 km from Innichen), via Moos in Piano Fiscalino/Fischleintal . Park at the Dolomitenhof hotel at the end of the Fiscalino/Fischleintal valley, walk pass the Capanna Fondovalle Fiscalina/Talschlusshütte hut, at the marked path junction, follow no.102 via Valle Sasso Vecchio/Altensteintal on the right side of the creek. This is shortest option,
   from Dolomitenhof till Locatelli hut takes just under 3 hours. Longer option is to fork left at aforementioned path junction and follow marked path no. 101 for Refuge Zsigmondy-Còmici (2 and half hours from the Dolomitenhof)
   and further over the Passo Fiscalino/Obernbacher Joch pass till   Refuge Pian di Cengia / Büllelejoch Hütte . From the refuge furter westbound above the sweet blue Laghi dei Piani/Bödenseen lakes. Once you see the lakes, that means only 15 minutes of walk till the Locatelli hut. Pian di  Cengia hut - Locatelli hut, just over 60 minutes.
   Going back to the Dolomitenhof parking and your car, of course you can use much shorter path no. 102 described few lines above.
   

As said, Sasso di Sesto/Sextner Stein is pretty much a backyard ascend of the Rifugio Locatelli/Dreizinnenhütte
located at the Forcella di Toblìn/Toblinger Scharte pass.
Hut fixed phone +39 0474/972002 email:dreizinnenhuette@rolmail.net
open June-September
140 beds, 6 bunks in winter room

Going there just because of Sasso di Sesto is not quite likely, so here are some further options:

Possible hut-to-hut traverse from the Rifugio Locatelli/Dreizinnenhütte:
Rifugio Auronzo/Auronzohütte -  Rifugio Lavaredo/Lavaredohütte
This is  the well known and frequently undertaken hike looping around the ubiquous 3 Lavaredo tops (Tre Cime di Lavaredo/Drei Zinnen). From the Locatelli hut fork right (westbound) and follow the marked  path no.105. Lavaredo  tops are on your left, youll soon reach small Col Forcelina with 2 or 3 cute little lakes, pass the lakes, path slightly ascends to the small green plateau offering last "postcard" type view of the Lavaredo tops. Now, we are gradually descending and winding leftbound enjoying nice views of the Cristallo massif  and  the Cadini peaks. At the Forcella del Col de Mezzo, we are now almost parallel with the westenrmost of the Lavaredo tops. Easy stroll takes us down to the Auronzo hut.
The first 90 minutes of our loop-round hike have just gone by. From the Auronzo hut, continue due east pass the memorial chapel Capella degli  Alpini and follow marked path no.101. Now, you are forced again to stare at the walls of the Lavaredo tops (on your left), however, one has an enjoyable option of the right side views, particulary of the Cadini peaks and Marmarole. Pass the rocky Prati di Lavaredo and this is about it. One may finish looping  by hitting the accross the scree trail for Forcella Lavaredo/Paternsattel and back to the Locatelli hut (total time 3 and half hours, roughly)

If you plan to  give a try to other peaks by starting from the Locatelli hut, here is small list of options

• Forcella del Camoscio/Gams Scharte - Monte Paterno/Paternkofel (2744m)
  just under 2 hours, described on a separate Summitpost page
• Crodòn di San Candido (Rocca Novale)/Innichenriedlknoten (2891m)
   round 3 hours
• Torre Toblin/Toblinger Knoten 2619m
  (described on separate Summitpost page)

Weather:
for the whole  province of Bolzano:
http://www.suedtirolerland.it/suedtirol/siteSLenSLwetter.phpQMQ.html

Maps:  
Tabacco 010  Dolomiti di Sesto/Sextener Dolomiten 1:25000
freytag & berndt  WKS 10 Sextener Dolomiten-Cortina d'Ampezzo 1:50000

Links:
online map
Sextner Dolomiten nature park

Security:
Emergency mountain rescue, dial 118