The surrounds of India Gate form the majestic centre of New Delhi and boasts some of the Indian capital's widest open spaces, as well as some of the finest examples of India's Raj architecture in the city. Hyderabad House, the Delhi High Court, the Supreme Court of India and the Patiala House Court are all beautiful examples of their style and all in the immediate proximity of India Gate. From here, the Rajpath is a grand processional route leading to the Houses of Parliament. The Parliament buildings are an imposing classical block, standing behind grand red sandstone walls. Visits can be arranged though it involves a lengthy application process through the embassy.
This area is also rich with museums and galleries. Most notable is the National Museum which houses 200,000 works of art and cultural artefacts spanning 5,000 years of history. The National Gallery of Modern Art and the Indira Gandhi National Centre for the Arts are also well worth a look. Due south from India Gate is bustling Khan Market and the beautiful Lodi Gardens. It's here that you'll find the stunning tomb of Muhammad Shah Sayyid, a fantastic octagonal stone structure with much of its original 15th century ornamentation still visible.
The area immediately to the south of the Old Delhi Railway Station is perhaps the most exhaustingly hectic and deafeningly noisy in all Delhi. It is also the area where you'll find most of the city's top sights and the location of some of its oldest neighbourhoods. This area is bounded to its east by the Red Fort on the bank of the Yamuna River. Whilst the Red Fort has definitely seen better days (the majority of the buildings of the Red Fort were destroyed in battle during the Indian uprising and those that remain have been largely stripped of their finery)it's still worth a visit for the sheer scale of the place and to see the grand red sandstone architecture.
Outside the Lahore Gate, the Netaji Subhash Marg runs; a vast highway lined with fast food diners and glitzy clothes shops. Worth a look in here is the Digambar Jain Temple. It's a little oasis of calm and houses the utterly bizarre bird hospital. Running west from here is the Chandni Chowk district. This is the traditional bazaar of Old Delhi and a fascinating area to explore. Don't expect any souvenir shops, in fact there's probably little shopping for tourists to do here. Instead it's a fascinating insight into everyday life in Delhi and an exciting place to get lost in. Emerging at the southern end of Chandni Chowk, you'll find the Jama Masjid - a must-see sight on any Delhi holiday. This is the biggest mosque in India and despite the growth of the city around it, it's lost none of the splendour of its Mughal architecture. For a small fee, you can climb the minaret for some extraordinary views of the city.
Whilst there's very little in the way of tourist sites in Connaught Place, its status as one of the main central business districts of Delhi means it's likely you'll end up visiting it at some point. Most banks, airline offices and tourism offices are located here and there are a few nice restaurants and cinemas. Connaught Place is a series of concentric rings of white colonnaded colonial architecture. Whilst the effect must have been fairly regal in its day, it has since been overrun by neon signs, advertising billboards and other such clutter. The area is also a massive shopping hub for Delhi and whilst you might not feel inclined to buy anything, the vast underground rabbit warren that is the Palika Market is well worth a look for an impression of the affluent side of Delhi.
If you're not travelling on a budget, you'll probably find no reason to visit Paharganj. It's filthy - even by Delhi's standards - potentially unsafe, noisy, crowded and - at least on the surface - fairly charmless. However, it remains a Mecca for backpackers owing to its dirt cheap hotels, dirt cheap restaurants and dirt cheap souvenir shops. It's also just across the road from the New Delhi Railway Station from where most trains to Rajasthan and Punjab leave. Given that long distance trains leave early in the morning, it can be convenient to have a hotel in Delhi just a five-minute walk from the station. You'll need to watch your pockets on Paharganj and be aware of hustlers and scams, but if you can get beyond these drawbacks it can be a fun and lively, as well as extremely cheap, place to spend a night or two.