The handsome, glass-clad Helena is a huge rental apartment slab tower on 57th Street at 11th Avenue that was erected in 2005 by the Durst Organization and Sidney Fetner Associates, who had previously erected another rental tower, the Epic south of Herald Square.

The Helena, which was designed by Fox & Fowle, is one of the "greenest" residential buildings in the city. It is 38 stories tall and has 597 apartments.

It features hardwood oak floors from certified sustainably harvested forests, Zodiaq countertops that are cleaner and safer than granite and other natural stones and more durable, carefree, stain and heat resistant, and low-emitting materials for paints, adhesives, sealants and carpeting to reduce in-building pollution, including odors and potential irritants.

Console heat pumps in each room allow residents to heat or cool individual rooms year round and the building supplies water to these pumps at a constant 85 degrees from two separate systems and a master switch just inside the apartment front door allows residents to set back their heat pump's thermostat, decreasing their energy bills while they're out.

Outdoor air used to ventilate the corridors is filtered by ultraviolet light to help protect residents from airborne pathogens.

The building's garage has plugs for electric/hybrid vehicles.

The building has an internal sewerage treatment system that purifies wastewater and recycles it for use in the building's toilets.

Window walls are fitted with "trickle vents" that permit residents to introduce fresh air without opening any windows and the windows are treated to reflect the sun's damaging ultraviolet rays.

The building has a gold LEED (Leadership in Energy and Environmental Design) rating.

Twenty percent of its units are "affordable."

Overhead light fixtures and switched lighting are controlled by a master switch that allows residents to easily shut them off without affecting computers and other non-switched appliances.

The building has a concierge, a health club, valet services, and a shuttle bus and the roof deck has solar panels.

There are cross-town buses on 57th Street and the building is not too far from the Lincoln Center for the Performing Arts and its location offers impressive vistas in most directions.