Laudator Temporis Acti

Stephen Hinds, "Landscape with Figures: Aesthetics of Place in the Metamorphoses and its Tradition," in Philip R. Hardie, ed., The Cambridge Companion to Ovid (Cambridge: Cambridge University Press, 2002), pp. 122-149 (at 126, footnotes omitted):

Furthermore, when a description of place interrupts or punctuates a narrative, as characteristically in Ovid's Metamorphoses and other epics, it has available a stereotyped entry formula to set it apart from its surrounding context, often couched in a 'timeless' present. locus est or more commonly est locus is the default opening ('there is a place...'), as in the first instance of the pattern in extant Latin poetry at Ennius, Ann. 20 (reprised by Virgil at Aen. 1.530),

est locus Hesperiam quam mortales perhibebant

or as in a famous Virgilian instance even earlier in the Aeneid (1.159)

est in secessu longo locus...

typically picked up by a resumptive demonstrative or relative at the point of transition from description back into narrative (thus huc at Aen. 1.170). The initial est locus — which may lurk as a(nother) metaformular pun within Horace's sed nunc non erat his locus — is regularly varied by the naming of the place or object described: est specus, est nemus, stagnum est, fons erat.

C.J. Fordyce, commentary on Vergil, Aeneid 7-8 (Bristol: Bristol Classical Press, 1985), pp. 161-162 (on 7.563 ff. est locus ... hic):

the abrupt introduction of a short piece of local description which is later picked up and related to the narrative in a following clause is a piece of epic technique inherited from Homer: cf., e.g., Od. iv.844 ff. ἔστι δέ τις νῆσος...τῇ, Il. ii.811 ff. ἔστι δέ τις προπάροιθε πόλιος αἰπεῖα κολώνη...ἔνθα, xiii.32 ff. ἔστι δέ τι σπέος...ἔνθα. (So also Aesch. Pers. 447 ff.: Hellenistic epic continued the device, e.g. Ap. Rhod. i.936, iii.927.) Virgil uses the 'Homeric' opening with est again in i.159 ff. 'est in secessu longo locus...huc', ii.21 ff. 'est in conspectu Tenedos...huc', 713 ff. 'est urbe egressis tumulus...hanc...sedem', v.124 ff. 'est procul in pelago saxum...hic', viii.597 ff. 'est ingens gelidum lucus prope Caeritis amnem...haud procul hinc', xi.522 ff. 'est curuo anfractu ualles...hanc super', Geo. iv.418 ff. 'est specus ingens...his...in latebris': similarly in this book 59 ff., 170 ff., 607 ff. He has variations of the formula in iii.13 ff. 'terra procul uastis colitur Mauortia campis...huc', 73 ff. 'sacra mari colitur medio gratissima tellus...huc', 210 ff. 'Strophiades Graio stant nomine dictae...huc', 533 ff., viii.416 ff. Ovid uses the device often, e.g. Met. xi.592 ff., F. iv.337 ff., vi.9 ff., Her. 16.53 ff., Am. iii.1.1 ff.; so Propertius, iv.4.3 ff., 6.15 ff. For a prose example cf. Livy i.21.3 'lucus erat, quem...eum lucum'. On this device see E. Fraenkel, De Media et Noua Comoedia Quaestiones Selectae (Göttingen, 1912): but he does not distinguish clearly between examples of a deliberate device of literary narrative and those of a casual conversational manner of speech (e.g. Plaut. Aul. 674 ff.; Ter. Ad. 576) which is natural in any language.

For another example in Vergil's Aeneid, see 1.441 ff. (lucus in urbe fuit media, laetissimus umbra, / quo...loco...hic...hoc...in luco...hic). Note to myself: prose analogues to Vergil's est urbe egressis tumulus... (Aen. 2.713), e.g. in Pausanias and in periplus authors?

K.W. Gransden, commentary on Vergil, Aeneid 8 (Cambridge: Cambridge University Press, 1976), p. 158 (on 8.597 est ... lucus):

opening formula for an ecphrasis or set-piece of the kind known as topothesia, description of place. The 'est' opening (= 'there is') is normal, e.g. Ennius, Ann. 23 V² est locus Hesperiam quam mortales perhibebant: for a variation see sbove 416n. This figure is first found in Homer (e.g. the gardens of Alcinous in Od. 7.112 ff., the uninhabited island which lies across the bay from the Cyclopes in Od. 9.116 ff.) Other exx. in the Aen. are at 1.159 ff., 4.480 ff., 7.563 ff., 11.522 ff. See Williams, TORP 637 ff. The figure also occurs in English, e.g. Hamlet 4.6.167 'There is a willow grows aslant a brook, / That shows his hoar leaves in the glassy stream; / There with fantastic garlands did she come...'

"Williams, TORP" is Gordon Williams, Tradition and Originalty in Roman Poetry (Oxford: Clarendon Press, 1968), unavailable to me.

Heinrich Lausberg, Handbook of Literary Rhetoric, tr. Matthew Bliss et al. (Leiden: Brill, 1998) § 819, pp. 365-366:

The description of places as a digression (Quint. Inst. 4.3.12) in narratio (cf. § 342) also bears the designation τοπογραφία: Quint. Inst. 9.2.44 locorum quoque dilucida et significans descriptio eidem virtuti (scil. evidentiae (cf. § 810)) assignatur a quibusdam, alii τοπογραφίαν dicunt; Empor. p.569,25 demonstrationes vero urbium locorumque iam non demonstrationes, sed topographiae a plurimus existimantur, Quint. Inst. 4.3.12 laus ... locorum ... ut descriptio regionum.

Topography as the description of a geographical place mentioned by name is distinguished by some from topothesia as the description of a fictitious place: Schem. Dian. 11 τοπογραφία est loci descriptio, ut apud Vergilium: "est locus Italiae medio sub montibus altis, / nobilis et fama multis memoratus in oris, / Ampsancti valles: densis hunc frondibus atrum / urget latus nemoris, medioque fragosus / dat sonitum saxis et torto vertice torres..." (Verg. Aen. 7.563); — ibid. 12 τοποθεσία est loci positio, cum describitur locus, qui non est, sed fingitur, ut "est in secessu longo locus: insula portum / efficit obiectu laterum, quibus omnis ab alto / frangitur inque sinus scindit sese unda reductos" (Verg. A. 1.159). — Plb.Rh. iii p.109,4-13 gives exactly the reverse definitions for τοποθεσία and τοπογραφία respectively.

Introduction by means of the (also variable) formula est locus, whether the place is fictitious or real, is frequent: Verg. A. 7.563 (see above); Verg. A. 1.159 (see above); Sen. Tro. 1068; Ov. Met. 8.788; 11.592; 12/39; Rem. 549.

From French literature (cf. Mornet, Clarté p. 75) may be quoted Henriade 1.193 Non loin de ce rivage, un bois sombre et tranquille, / Sous des ombrages frais, présente un doux asile: / Un rocher...