Here are some more Sandbox-Dungeon-Wilderness links I have found on my travels in the dark and inimical places of the OSR web.
Advanced Darkness @ Knight at the Opera - nice thoughts on making light important
The Overloaded Encounter Die @ Necropraxis - a classic solution to Dungeon logistics
The Hazard System - an update
There is no light @ Illusory Sensorium - tracking torches is a false idol
Movement and action economy @ Traverse Fantasy - why you need a torchbearer
Megadungeon Monday series @ The Angry GM - how to build a megadungeon in many steps
Why I run my dungeons as pointcrawls @ The Pastel Dungeon
The Forest Deep Part 1 - creepy forests that are out to get you
Choices Information and Meaning - choices should be real, meaningful and informed
Hexcrawls are megadungeons - and pointcrawls too
Make your hexcrawls smaller - and more dense
The classic dungeon crawl theory @ All Dead Generations - a great series on dungeon crawls
More OSR Links @ The Links to Wisdom OSR Wiki
Pointcrawls - The path is more important than the ‘direction’ @ vdonnutvalley
Pointcrawls Applied: The Escalating Encounter Die @ the adventuring day
Some more adventure reviews @ Axian Spice - scroll down for the OSR ones.
Axian's Falkrest Abbey is a nice little introductory adventure with great organisation.
Some good advice from Reddit on running old school adventures.
And an old thread from enworld identifying a key difference between old and new school D&D. Namely, do you want combat as sport or combat as war.
Monster tactics @ The monsters know what they're doing
Path-crawl and point-crawl @ daimon-games
Corelands, Borderlands and the Weird @ Hill Cantons
Wilderness dungeons @ signs in the wilderness
Adventure reviews and more @ tenfootpole.org
Bryce Lynch's adventure design tips @ Into the dark's summary of the tenfootpole approach