The best characterized herpesvirus is the important human pathogen, herpes simplex virus type 1 (HSV-1). The HSV-1 virion comprises 1) an icosahedral capsid which encloses the genome, 2) a surrounding variable proteinaceous layer called the tegument and 3) an enclosing lipid envelope with glycoprotein spikes. The capsid shell has the form of a T=16 icosahedron and has been studied extensively both as an isolated capsid and as the core of the virion. Several proteins have been described as minor capsid components, prominent among which is pUL6. A dodecameric ring of pUL6 proteins forms the portal, which replaces a penton at one capsid vertex. The portal has a central channel and by analogy with tailed bacteriophage, is believed to form the route for transit of the DNA into and out of the capsid. Here we describe a cryo-ET reconstruction of the intact HSV-1 virion that identifies the portal vertex and reveals a previously unsuspected structure that spans the tegument, linking the capsid to the envelope, which we term the “tegument cylinder”. The position and nature of this structure suggests possible roles in virus assembly or transport.