World Fellowship Centre, Conway, New Hampshire

Another unbuilt Marion Mahony Griffin project prepared at the instigation of Lola Lloyd, 1942. 

Hill Crystals and Rosary Crystals, Boerne, Texas

This project, by Marion Mahony Griffin commissioned by Lola Lloyd, was not built.

'The drawing "Hill Crystals and its Suburb Rosary Crystals" is dated January 1943. There are 118 residential sites distributed according to modified Radburn and Garden City planning principle, with common nature reserves joining them... At the centre of each is a circle with a building and in the residential area a nature reserve similar to those in Castlecrag.' Anna Rubbo, 'Marion Mahony's Return to the United States; War, Women and "Magic"' in David Van Zanten (ed) Marion Mahony Reconsidered University of Chicago Press, Chicago 2011, pp. 134-5

Unnamed IR, Rue de l'Angouleme, Annecy, France

It's here. Why was I sniffing around Annecy on google maps? 

Because the 2012-15 French supernatural series Les Revenants (remade in the US as The Returned) is set in a modernist village in regional France (and filmed largely in Annecy). In the second episode of the second season, Claire Séguret – the mother of two ‘returned’ (undead) girls – wanders, disoriented, down a treelined path into a cultivated park space where, suddenly, a host of her zombielike former neighbours appear around her. There is no retreat possible; clearly, there is only one way in and one way out of this park. We do not see what happens to Claire, but we do see her come to consciousness, bruised but alive, in the same small park.

I can't tell whether this is the park in question, although the pathway to the park Claire finds herself in is similarly tree-lined. But google maps being road-based as it understandably is, there's no way of seeing inside the space itself (just a very hazy aerial view). 

By the way a small point: just wanted to say I'm trying very hard to get the accents right on Angouleme but blogger keeps cleaning the word up! 

Maddern Square, Footscray, Victoria

The City of Footscray District Centre Study of 1992 labels Maddern Square as 'public open space' and even recommends (on p. 76) that (as 'Maddern Reserve') it be identified as one of 'a number of minor pathway opportunities' but its status is unclear. Unsurprisingly a sardonic review from yelp gives a flavour of the place and the locals:

Maddern Square is our favorite haunt on the way from Cheaper by Miles to the Footscray Market. The square is perfectly designed to catch all of the free flowing litter and collect a fine assortment of broken glass and wine cask bladders from a Thursday night to Sunday arvo. Since the closure of the Rotunda in the Railway Gardens, Maddern Square has become the defacto home of late night parties out of the spotlight of the world class Mall that it funnels into and a hot spot to take the kids to see what drugs can do. Maddern Square is full of potential, don't get me wrong. It's a (well known) secret car park if you're going to the market and a great place to rinse a syringe or two before urinating behind the old Godfreys Cleaning store. Sure, it has real grass instead of asto turf, trees that have been pollarded by aspiring gardeners and concrete seating to whittle the time away reading the walled wisdoms, but what it needs is a bottle shop, public toilet and an army of large garbage bins with basketball hoops for incentive. So if you want to see a mall without the shops, but with all of the charm of the Nicholson St showcase (whilst having cars drive at you), Maddern Square is your heaven.

Another states:

I am waiting for the day that the shops turn inwards towards this space and it becomes an inviting square.  The structural pieces placed here at expense does nothing to enhance the square presently apart from detract from the assorted debris. Lighting, greening and coffee and cakes, a performance space would turn this opportunity pending around.

More work needs to be done on the history and projected use of Maddern Square. You can find the space in question here. 

Karl Langer, hypothetical, c. 1945

I found this while reorganising my office and I don't know much detail but will add it in if and when it comes to hand.